Supply, demand and government policies

Based on a course by Federica Sbergami

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Introduction to microeconomics

Microeconomics Principles and Concept ● Supply and demand: How markets work ● Elasticity and its application ● Supply, demand and government policies ● Consumer and producer surplus ● Externalities and the role of government ● Principles and Dilemmas of Public Goods in the Market Economy ● The costs of production ● Firms in competitive markets ● Monopoly ● Oligopoly ● Monopolisitc competition

Government intervention in economic markets takes the form of a variety of strategies, each targeting specific aspects of the market to achieve defined socio-economic objectives. These government interventions, which are essential for regulating the economy, include measures such as bans, product regulations, quantity and price controls, and the use of taxes and subsidies.

The outright banning of certain markets is a striking example of government intervention. This extreme measure is generally adopted for reasons of public safety, health or the environment. A case in point is the ban on illegal drugs, where governments seek to protect public health and reduce crime. Similarly, the ban on asbestos-containing products in many countries is a response to public health concerns about its harmful effects on the lungs.

In terms of product regulation, governments often impose strict standards to ensure the quality, health and safety of products. For example, vehicle emission regulations aim to reduce air pollution, while food standards guarantee the safety and quality of food products. These regulations protect consumers and help preserve the environment, but they can also increase production costs for companies.

Quantity control is another form of intervention, used to regulate the supply of certain products on the market. During the Second World War, for example, many countries set up rationing systems for essential products such as food and fuel, thus ensuring a fair distribution of limited resources. In international trade, import quotas are often used to protect local industries from foreign competition.

Controlling prices by setting price ceilings or price floors is another strategy used to influence the market. Price ceilings can help make essential goods more affordable during crises, as was the case with price caps on essential medicines in some countries. Price floors, meanwhile, are often used in agriculture to ensure a minimum income for farmers, although this can sometimes lead to overproduction and inefficiencies.

Finally, taxes and subsidies are powerful fiscal tools for influencing market behaviour. Taxes on tobacco and alcohol, for example, aim to reduce the consumption of these products, which are harmful to health. Subsidies, on the other hand, can encourage beneficial activities, such as renewable energy subsidies to promote a sustainable energy transition.

These government interventions have a profound impact on the balance of supply and demand in markets, and therefore on the economy as a whole. They require careful planning and ongoing evaluation to ensure that they achieve the desired objectives without causing undesirable effects. The complexity of these interventions lies in the fact that they must take account of the needs and reactions of the various market players, while balancing economic, social and environmental objectives.

Price control

Price controls

State price controls are a form of economic intervention used to regulate market prices in situations where the equilibrium price, i.e. the natural price resulting from the meeting of supply and demand, is deemed to be inadequate or unfair. This intervention can take different forms depending on the context and the objective, and generally involves setting price ceilings or floors for certain goods or services. A classic example of price controls is interest rate limits, often referred to as usury limits. This measure is put in place to prevent lenders from charging excessively high interest rates, particularly on consumer loans and credit cards. By setting a maximum rate, the government seeks to protect borrowers from abusive lending practices and maintain financial stability.

Minimum wages are another common form of price control. Here, the aim is to ensure that workers receive a sufficient income to live on. By setting a statutory minimum wage, the state seeks to combat poverty and ensure that workers are paid fairly. However, the minimum wage can also be a source of debate, with some arguing that it could reduce employment opportunities for low-skilled workers.

Rent control is another intervention where the state sets a cap on the amount that landlords can charge for renting out accommodation. This measure is usually taken in high-density urban areas where rents can rise very high, making housing unaffordable for many residents. Rent controls aim to make housing more affordable, but they can also discourage investment in rental accommodation and limit the supply available.

Finally, agricultural support prices are a form of price control where the state sets a floor price for agricultural products. This measure aims to protect farmers from fluctuations and volatility in market prices, thereby guaranteeing a stable income. However, support prices can lead to overproduction and market distortions, often requiring the government to buy and store surpluses.

These forms of price control, although motivated by positive intentions, can have complex and sometimes undesirable consequences. Balancing the social and economic benefits of these policies against their potential side-effects is a major challenge for policy-makers. It is crucial to continually assess the impact of these interventions and adjust them to meet the changing needs of the economy and society.

State intervention in prices may also be motivated by the need to correct market inefficiencies caused by an imbalance of power between buyers and sellers. In some cases, a market player may have sufficient power to significantly influence the price of a good or service, thereby distorting the efficient functioning of the market. Price controls are a strategy that the state can use to restore balance and ensure fairer competition. An important aspect of price controls is that they are often less costly than introducing subsidies. Subsidies, although effective in supporting certain industries or in making certain goods and services more affordable, have to be financed by tax revenues, which implies a cost for the state and, ultimately, for taxpayers. Price controls, on the other hand, do not require direct state expenditure, which makes them an attractive option in certain contexts.

It is also important to note that price control decisions are not always taken solely on the basis of objective economic analysis. Sometimes they may be the result of pressure from lobbying groups seeking to take advantage of a rent-seeking situation. These "rent-seeking activities" can lead to policies that favour certain groups or industries to the detriment of overall economic efficiency or equity.

Finally, price controls can be used as a tool to control high inflation. In situations where inflation is spiralling out of control, the state can impose a price freeze or price ceilings to prevent costs from continuing to escalate. However, while this may offer temporary relief, it does not address the underlying causes of inflation and can lead to shortages if prices are kept below the level where supply meets demand.

In all cases, it is essential to recognise that price controls, while useful in certain circumstances, are an intervention that should be used with caution. It must be accompanied by a rigorous assessment of its potential impact, both immediate and long-term, on the economy and society.

Price ceilings

A price ceiling, or maximum price, is an upper limit set by the government above which it is forbidden to sell a good or service. This intervention is generally implemented when the government considers that the market equilibrium price, i.e. the price at which supply equals demand, is excessively high and potentially harmful to consumers. The main objective of a price cap is therefore to make goods or services more affordable, particularly for essential goods such as housing, energy or food.

It is important to stress that the effectiveness of a price cap depends on how it is positioned in relation to the equilibrium market price. If the price cap is set above the equilibrium price, it is considered non-binding and has no immediate effect on the market. Sellers can continue to trade at or below the equilibrium price without breaching the limit imposed. However, a price cap becomes binding and has significant effects on the market when it is set below the equilibrium price. In this case, the price is artificially maintained at a lower level than the market would have naturally determined.

When the price cap is binding, it can lead to several economic consequences. Firstly, it can create a shortage, because at a lower price, demand increases while supply decreases. For example, strict rent controls can lead to a shortage of available housing, as landlords may be less inclined to rent out their properties or invest in new homes. In addition, price ceilings can lead to a decline in the quality of goods and services, as suppliers look for ways to cut costs in the face of reduced profit margins. In addition, poorly designed or applied price ceilings can lead to black markets, where goods or services are sold illegally at prices above the ceiling. This can occur when demand significantly exceeds the supply available at the legal price ceiling.

The graph below illustrates a market with intervention in the form of a price ceiling. The graph shows two curves: the supply curve (in green) rising towards the right, indicating that the higher the price, the greater the quantity offered; and the demand curve (in red) falling towards the right, indicating that the lower the price, the greater the quantity demanded.The point where these two curves cross is identified as the equilibrium price, which in this case is set at €3, and the equilibrium quantity, which is 100 ice creams. This equilibrium point indicates the price where the quantity of ice cream that sellers wish to sell is exactly equal to the quantity that buyers wish to buy.

Above the equilibrium point, we have a horizontal line marked "Ceiling price" set at €4. This ceiling price is defined above the market equilibrium price. As indicated in the title, it is a ceiling price which is not binding, because it is set at a level above the price at which the market would naturally balance. In other words, since the ceiling price is above the price at which the quantity offered equals the quantity demanded, it does not directly affect the functioning of the market. Transactions can continue at the equilibrium price without being hindered by the price ceiling. In practice, a non-binding price cap such as this has no immediate impact on the market. It is put in place either for political reasons, to show an intention to regulate without disrupting the market, or as a preventive measure to prevent prices from rising higher in the future. However, if market conditions evolve in such a way that the equilibrium price rises above €4, then the price cap would become binding and begin to have associated effects such as shortages or queues.

The quantity traded at a given price is the smaller of the quantity offered and the quantity demanded. In a market, at a given price, the quantity traded is determined by the smaller of the quantity offered and the quantity demanded. This concept is crucial to understanding how markets work and the effects of interventions such as price caps. When the price of a good or service is at its equilibrium level, the quantity of that good or service that sellers are prepared to sell (quantity offered) corresponds exactly to the quantity that buyers are prepared to buy (quantity demanded). This is known as market equilibrium, where supply and demand are in perfect harmony, and there is no surplus or shortage.

However, when the price is artificially set below the equilibrium level (as in the case of a price ceiling), the situation changes. At this lower price, the quantity demanded by consumers generally increases, as the good or service becomes more affordable. At the same time, the quantity offered by producers falls, as it becomes less profitable for them to produce or sell the good or service. In this case, the quantity traded is equal to the quantity offered, which is smaller than the quantity demanded. This leads to a shortage, as there are more people wanting to buy the product than are available at the set price. Conversely, if the price is artificially set above the equilibrium level (as in the case of a price floor), the quantity demanded decreases while the quantity offered increases, leading to a surplus on the market.

In a free market, the quantity traded is determined by the point where supply and demand meet. Any intervention that alters this equilibrium point, such as the introduction of price ceilings or floors, causes an imbalance between the quantity offered and the quantity demanded, leading to shortages or surpluses.

The introduction of a price ceiling, although intended to make a product or service more affordable, can have unexpected and sometimes unfair consequences. When the government sets a price ceiling below the equilibrium market price, the good or service becomes cheaper, which increases demand. However, at this lower price, producers may be less inclined to offer the same level of quantity, creating a shortage. In this situation, there are not enough goods or services available to satisfy everyone who wants to buy at the ceiling price. This imbalance often leads to queues and other forms of rationing, as there are more people than products available. In this context, wealthier consumers may have an advantage, as they may have more means of accessing the limited product or service, for example, by paying for priority access or using their influence. This can lead to a form of discrimination where people on low incomes, although theoretically the beneficiaries of these price ceilings, find themselves excluded from the market.

In addition, inefficient price caps can encourage the development of black markets. In these markets, goods or services are sold illegally at prices above the legal ceiling, which can exacerbate inequalities, as only those who can afford to pay higher prices have access to them. These side-effects of price controls underline the importance of careful design and implementation of public policies. It is essential that policy-makers take account of these potential consequences and explore alternative or complementary mechanisms to achieve their objectives without introducing new inequalities or inefficiencies into the market.

This graph illustrates a market in which a binding price ceiling has been introduced. This graph shows the supply and demand curves, as in the first example, but with a significant difference in the position of the price ceiling. The natural equilibrium price on this market is €3, at which point the quantity offered by producers corresponds to the quantity demanded by consumers. However, the government has introduced a ceiling price of €2, which is lower than the equilibrium price.

At this price ceiling level, the quantity of ice cream demanded is greater than the quantity that producers are prepared to offer. This creates a shortage, as shown in the graph, because at €2 there are more consumers willing to buy ice cream than there are producers willing to sell it at that price. The points on the supply curve and the demand curve do not meet, which means that there is a deficit between the quantity of ice cream that consumers want to buy and what is available on the market.

This shortage situation can lead to a number of secondary outcomes, such as long queues for ice cream, as consumers compete for a limited number of available products. In addition, it can encourage unofficial economic activities, such as a black market where ice cream could be sold at a higher price than the legal ceiling. In theory, price ceilings are designed to help consumers by making goods and services more affordable. However, as this graph illustrates, if they are set too low, they can actually disrupt market equilibrium and lead to undesirable effects that undermine market efficiency and can potentially disadvantage the very consumers they are designed to help. For this reason, it is essential that price ceilings are set taking into account the balance between supply and demand to avoid such negative consequences.

Price ceilings: short vs. long term

In a long-term context, the price elasticities of supply and demand tend to be higher because of the greater ability of producers and consumers to adjust their behaviour in response to price changes. The price elasticity of demand measures the sensitivity of the quantity demanded to a change in price. If consumers have more time to find substitutes or adapt to a price change, their response will be stronger, which means a higher elasticity. Similarly, the price elasticity of supply indicates the sensitivity of the quantity offered to a change in price. Over time, producers can adjust their production levels in response to changes in market prices.

When a binding price ceiling is in place, producers have little incentive to invest and increase production because the returns on these investments are limited by the price ceiling. If the price is kept below the level that would allow normal profitability, producers may not invest in improving quality or expanding production capacity. In the long term, this can lead to a decline in the quality of goods produced as producers look for ways to cut costs to maintain their economic viability in a price-constrained environment. With less investment in the sector, supply does not adjust to meet increased demand, exacerbating the existing shortage. In a market without price controls, higher prices would act as a signal to attract new producers or encourage existing producers to increase production. But with a price ceiling, this signalling mechanism is altered.

The long-term result of a binding price ceiling is reduced supply, increased scarcity and reduced quality. These consequences can have a negative impact on the general well-being of consumers, particularly those on low incomes, who could be hardest hit by the reduced quality and availability of essential goods and services. This underlines the importance for price control policies to take account of long-term impacts and to seek balances that encourage investment while protecting consumers.

Rent control is a government intervention that seeks to regulate the housing market by setting a legal maximum for rents or limiting annual rent increases. This policy is generally implemented in areas where the cost of housing has risen so significantly that a large proportion of the population is struggling to afford a home. The aim is laudable: to maintain affordability and stability in a sector that is crucial to people's well-being. However, this economic strategy is not without its drawbacks and complexities. When rents are kept below the level that would be set by the free market, this can lead to an inappropriate allocation of resources. Landlords, faced with limited financial returns, may have no incentive to invest in the maintenance or improvement of their properties, which can lead to a gradual deterioration in the quality of the housing stock. In addition, property developers may be reluctant to build new homes if the expected returns do not justify the investment, which hampers the increase in the supply of housing and exacerbates the shortage.

These shortages are not just theoretical hypotheses; they are manifesting themselves in cities all over the world. For example, in New York and San Francisco, two cities well known for their rent control policies, the lack of affordable housing is a persistent problem. Despite intentions to make housing accessible, these cities have struggled with shadow housing markets where rents can far exceed regulated rates, creating a difficult environment for those not protected by rent control regulations. Landlords, faced with a large number of applicants for a limited number of flats, can become extremely selective. This can lead to discriminatory practices, sometimes subtly implemented through stricter rental requirements, which may include more rigorous credit checks or requests for additional financial guarantees. Thus, instead of helping the low-income population, rent control can paradoxically disadvantage them.

To mitigate these negative effects, some jurisdictions have explored complementary policies. For example, the Vienna model of social housing is often cited for its balanced approach. Vienna combines rent control measures with significant investment in social housing, providing a large quantity of affordable housing while maintaining high quality standards. It is clear that rent control, while well intentioned, can have perverse effects which require carefully calibrated policies to ensure that the objectives of affordability and housing quality are achieved without creating undesirable distortions in the market.

Application: rent control in the short term

The graph below illustrates the impact of rent control on the housing market in the short term, where supply and demand are relatively inelastic. The graph shows typical supply and demand curves: the supply curve is rising, indicating that landlords are prepared to offer more homes at a higher rent, and the demand curve is falling, showing that tenants demand fewer homes as the price rises.

Impact of rent control (price ceiling) in the short term (inelastic supply and demand)

The "Maximum rent" indicated by a horizontal line represents the ceiling price set by government regulations. This maximum rent is lower than the price that would naturally be established at the intersection of the supply and demand curves, which represents the equilibrium price of the market.

In the short term, where the reactivity of landlords and tenants to price changes is limited (i.e. elasticity is low), the quantity of dwellings available does not fall considerably in response to the rent cuts imposed by control. Similarly, the quantity of housing that tenants want does not increase enormously either. However, even with a low elasticity, the maximum rent imposed by control creates a shortage, because at this controlled price, the quantity of dwellings that tenants want exceeds the quantity that landlords are prepared to rent. In reality, this shortage can result in various difficult situations for tenants, such as longer waiting lists for flats, increased competition for available housing, and potentially poorer quality housing, as landlords have no financial incentive to maintain or improve their properties. In addition, the shortage can encourage black market activity where homes are rented at unregulated prices outside the official system.

The experience of several cities around the world shows that the consequences of rent control can be complex and often counter-productive. For example, both Paris and Berlin have experienced challenges with their rent control policies, leading to political and social debates about how best to provide affordable housing without disrupting the market or discouraging investment in housing stock. Ultimately, managing the housing market through rent control in the short term needs to be undertaken with care and complemented by policies that encourage the supply of housing and ensure its quality, so that the goals of affordability and availability are achieved without undesirable side effects.

Application: rent control in the long term

This economic graph shows the long-term effects of rent controls on the housing market, with more elastic supply and demand curves. This means that landlords' and tenants' reactions to price changes are more pronounced in the long term than in the short term.

Impact of rent control (price ceiling) in the long term (elastic supply and demand)

The "Maximum Rent" is indicated by a horizontal line below the point where the supply and demand curves would naturally cross, i.e. below the equilibrium market price. The horizontal distance between the supply and demand curves at the level of the maximum rent represents the housing shortage. The text "In the long term, the shortage worsens" emphasises that, over an extended period, market players have time to react fully to the constraint imposed by the maximum rent. Tenants seek to find more homes at this attractive rent, which increases the quantity demanded, while landlords are discouraged from offering rent-controlled homes, which reduces supply. This dynamic leads to an increased shortage in relation to the short term. Landlords may choose not to invest in new homes or maintain existing ones because the financial returns do not justify the costs. Tenants, on the other hand, are encouraged to consume more space than they need because the price is lower than what they would be prepared to pay in an unregulated market.

Real-life examples of this phenomenon include cities such as San Francisco and New York, both of which have highly regulated housing markets and where the challenges of finding affordable housing are well documented. Long-term price caps in these cities have contributed to very tight housing markets, with long waiting lists for regulated flats and an insufficient number of new homes being built to meet growing demand. This highlights the importance of considering the long-term impacts of rent control policies. While these policies may be designed to help tenants, without accompanying measures to stimulate supply, they can end up exacerbating the very problems they are designed to solve. Well-designed policies must therefore strike a balance between protecting tenants and encouraging investment in the housing stock to ensure a sufficient supply of quality housing.

Winners and losers from rent caps

Rent capping, like any intervention in the market, creates winners and losers because of its varied impacts on different economic players.

The winners from rent caps are typically those who already have an existing lease in a property where the rent is capped. These tenants benefit from rents that are lower than what might be charged on an open market, which can save them money or allow them to live in neighbourhoods where they could not otherwise afford to reside. In addition, new tenants who are lucky enough to find rent-capped accommodation also benefit from these regulated rents, which can help them stabilise their housing costs. However, the losers of this policy are often more numerous or suffer more significant losses. Landlords, faced with restrictions on the amount of rent they can legally charge, receive reduced income from their property investments. This reduction in income can discourage them from investing in the maintenance and improvement of their properties, or worse, cause them to withdraw from the rental market altogether, thereby reducing the overall supply of housing.

In addition, individuals looking for a home who are unable to find one are also losers in this system. The shortage created by rent caps means that there are fewer homes available than there would be in a market without price controls. These individuals may find themselves paying much more for unregulated housing or enduring precarious living conditions, sometimes even having to leave the areas where they work or study for lack of affordable housing. It is also important to recognise that rent caps can have secondary impacts on communities. For example, it can lead to economic segregation, where only those with rent-controlled accommodation can afford to live in certain neighbourhoods, while newcomers have to look elsewhere, often in less desirable or more remote areas.

The challenge with rent capping is to strike a balance that protects tenants without discouraging the supply of quality housing or creating wider inequalities within society. To achieve this balance, it is essential that rent caps are accompanied by policies that encourage investment in the housing stock and support the construction of new homes.

Rent caps, as a housing policy measure, raise important questions of fairness. The aim is often to protect tenants from sudden and excessive rent rises and to ensure that housing remains affordable for all. However, the beneficiaries of these measures are not always those who need them most, which can lead to inequalities and distortions in the housing market.

In cities such as Geneva, where the property market is particularly tight and rents high, reported cases of politicians or people on relatively high incomes benefiting from moderate rents as a result of the cap can seem particularly unfair. This can undermine confidence in the regulatory system and raise concerns about its effectiveness and fairness. The problem of fairness is exacerbated by the fact that the benefit of a rent cap is often linked to the length of the tenancy. Long-standing tenants, who signed their leases when rents were lower, benefit from rents well below current market rates. This creates an advantage for older residents or those long established in the area, while younger tenants, newly formed families, students and migrants face a much more expensive and competitive market. These latter groups are often forced to pay significantly higher rents for similar accommodation, simply because they enter the market at a time when rents are at their peak.

To address these imbalances, some jurisdictions have implemented social housing programmes that specifically target low-income families, young people and newcomers, ensuring that low-rent housing is allocated on the basis of need rather than seniority. Others have adopted measures that allow some flexibility in rent controls, such as exemptions for new buildings, to encourage the construction of new homes. It is essential that housing policies, including rent controls, are designed and implemented in a way that promotes equity and meets the needs of different segments of the population. This requires ongoing analysis and policy adjustments to ensure that the objectives of affordability and social justice are met.

Consequences/costs of rent control

Although the aim of rent controls is to increase the affordability of housing, they can have significant consequences and costs for society. In a context of scarcity induced by these controls, the housing market is transformed into a sellers' market, where landlords and housing providers have disproportionate power over excess demand. Here is a closer look at these effects:

• Rationing of demand: When there are more applicants than available rent-controlled housing, landlords can afford to be selective, which often leads to rationing. Waiting lists get longer, and it is not uncommon for homes to be allocated not to those who need them most, but to those with connections, recommendations or who match a preferred profile defined by the landlord. This can also fuel discrimination, whether on the basis of income, ethnicity, age or other factors, thereby reducing the fairness and efficiency of the housing market.
• Increased demands from suppliers: In a rationed housing market, landlords may impose stricter conditions on the selection of tenants. This may include requiring larger bank guarantees or deposits, proof of solvency or employment, and sometimes even months' rent paid in advance. Such requirements can create insurmountable barriers for tenants on low incomes or those without access to solid financial guarantees, reinforcing inequality and limiting access to housing for these groups.

Landlords may also favour a 'posh clientele', i.e. tenants who are perceived as less likely to cause problems or who can offer stronger financial guarantees. This can lead to a socio-economic homogenisation of neighbourhoods, with consequences for diversity and social cohesion. The social costs of these dynamics can be significant. They can reinforce social divisions and limit mobility, both geographical and social. In addition, the effort and costs associated with finding a home in such an environment can be substantial, with a negative impact on the well-being of individuals and families. To alleviate these problems, housing policies could include fairer and more transparent matching mechanisms, targeted housing subsidies, and investment in the construction of affordable housing to increase supply. Such measures could help to rebalance the market and reduce the inequalities created or exacerbated by rent control.

The development of a black market is one of the often overlooked consequences of rent control. This phenomenon can take several forms, but one of the most common is abusive subletting. In a context where rents are capped at a level below that of the open market, demand for affordable housing far exceeds supply. Tenants with rent-controlled leases may be tempted to sublet their flats for more than they are paying, thereby making an unauthorised profit. This practice may sometimes be justified by tenants as a way of offsetting other costs or earning extra income, but it can lead to situations where subtenants pay far more than the officially controlled rent, thereby defeating the original purpose of regulation. Subtenants find themselves in a precarious position: they often pay high rents, do not have the same legal rights as official tenants and can be evicted more easily.

Black markets can also reduce the transparency and fairness of the housing market. They make it difficult for the authorities to monitor and regulate the market, and they create unequal conditions for tenants who are legitimately seeking accommodation. It can also lead to inefficient allocation of housing, where flats are not necessarily occupied by those who need them most or are most able to pay the regulated rate. To counter the formation of a black market, stricter regulation and control measures are often necessary. This can include penalties for abusive subletting, better enforcement of existing regulations and awareness campaigns to inform tenants and landlords about the risks and penalties associated with participating in a black market. At the same time, increasing the supply of affordable housing and ensuring fair access to housing for all segments of the population can reduce the incentive to create and participate in unofficial housing markets.

Rent controls, although designed to protect tenants from rent rises and ensure affordable housing, can lead to numerous economic inefficiencies and losses for the community. One notable consequence is the discouragement of residential mobility. Tenants who benefit from a moderate rent in a controlled market may be reluctant to move, even if a change of accommodation would make sense for them because of a professional transfer, a change in the size of their family, or other changes in their personal circumstances. This can lead to under-utilisation of available housing, where people stay in flats that no longer meet their needs simply because the cost of moving would be too high compared to the favourable rent they currently pay. Secondly, rent controls can act as a brake on investment in the construction and renovation of new homes. Investors, faced with a potentially limited return on investment due to rent caps, may choose to put their money into other areas where returns are higher and less regulated. This can reduce the number of new builds and renovations, exacerbating the housing shortage problem and undermining the overall quality of the housing stock.

The misallocation of resources is another major inefficiency. Low-rent flats can often be occupied by older individuals or couples whose children have left home, leaving large areas underused. At the same time, growing families may find themselves cramped into homes that are too small because that's all they can afford on the open market, where prices reflect the shortage created by controls. This inadequate distribution of housing does not reflect the real needs of the population and can lead to situations where the available space is not used in the most efficient way. To resolve these inefficiencies, it is necessary to develop housing policies that are not limited to rent controls but also include measures to stimulate supply, such as tax incentives for construction and renovation, as well as targeted housing subsidies that directly support low-income households. In addition, policies that allow a degree of flexibility in rent controls can encourage mobility and better use of resources, for example by allowing rent adjustments when tenants change or by revising rent controls according to the size of the dwelling and the number of occupants.

Controlled rents: efficiency and imperfect competition

Market efficiency and the assumptions underlying models of perfect competition often do not apply to the housing market. In fact, the housing market is subject to many imperfections that may justify state intervention, such as rent control.

Firstly, housing as a service is extremely heterogeneous, with characteristics that vary widely from one property to another, even within the same neighbourhood. Differences can include size, quality, age of the building, nearby services, transport connectivity and other subjective factors such as the charm of a place or its history. This heterogeneity means that each housing unit is almost a market in itself, making comparisons and generalisations difficult. In addition, the costs of prospecting and searching are significant. Finding suitable accommodation often requires considerable research, and perfect information is virtually impossible to obtain. Potential tenants have to invest time and money to find a property that meets their needs, and even then they don't always have all the information they need to make an informed choice. This can include rental price history, potential problems with the property or neighbourhood, and the landlord's future intentions. Finally, the housing market can be considered 'thin', meaning that there are relatively few providers, particularly in smaller regions or cantons. This can give existing housing authorities and developers considerable market power, allowing them to set higher prices than they would in a more competitive market. In some cases, this can even lead to cartel behaviour, where suppliers agree on prices or conditions, further limiting competition.

These market imperfections can sometimes justify interventions such as rent controls to protect tenants' interests and ensure access to housing. However, such interventions must be carefully designed to avoid creating additional inefficiencies and must be accompanied by other measures to increase supply and improve market transparency. For example, policies that increase the number of dwellings available or support the entry of new players into the market can help to reduce the market power of existing large players and improve the overall efficiency of the housing market.

In a housing market characterised by imperfect competition, rent controls can be seen as an instrument to correct certain inefficiencies and inequities. The argument in favour of rent controls, in this case, is based on the idea that the market power held by a limited number of property owners or developers can lead to higher prices than those resulting from pure and perfect competition. By limiting the ability of these players to set rents freely, rent controls can help to keep prices at a more reasonable level, which could potentially improve the accessibility and efficiency of the market. Beyond efficiency, rent controls are often justified on grounds of social equity. In many societies, it is considered fair and necessary to ensure that all citizens, regardless of income, have access to decent and affordable housing. Rent control can be seen as a means of social redistribution, helping to protect low-income households from market fluctuations and the burden of potentially unsustainable rents. In practice, this means that rents are kept at a level where low-income tenants are less likely to spend a disproportionate share of their budget on housing.

However, it should be noted that for rent control to achieve the objectives of efficiency and fairness, it must be designed and implemented in such a way as to avoid the pitfalls mentioned above, such as housing shortages, deterioration in the quality of the housing stock, and discrimination in housing allocation. This could include measures such as targeting rent controls at the segments of the population that need them most, putting in place policies to incentivise the construction of new housing, and regulating to ensure that rent-controlled housing meets decent quality standards. To balance these considerations, housing policies can include a variety of tools, such as rent supplements for low-income tenants, tax credits for landlords who maintain and improve rental housing, and programmes to encourage the construction of affordable housing. By combining rent control with these other measures, it is possible to tackle the problems of equity and efficiency in a more comprehensive and effective way.

Price floor

The concept of a floor price, or minimum price, is the antithesis of a ceiling price in economic regulation. It is an intervention where the government or a regulatory authority establishes a legal minimum price for a good or service, below which transactions are not permitted. This measure is often put in place to protect the interests of producers or service providers by ensuring that the market price does not fall below a certain level, which could otherwise threaten their ability to cover production costs or maintain acceptable living standards. A common example of a price floor is the minimum wage in the labour market. The government sets the minimum wage to prevent workers from being underpaid and to ensure that they receive a fair wage that allows them to meet their basic needs.

However, just as a ceiling price must be above the equilibrium price to be binding, a floor price must be set above the equilibrium price to have a real effect on the market. If the floor price is set below the equilibrium price, where the quantity demanded is equal to the quantity offered, it will have no immediate impact on market transactions since the natural market price is already higher than the floor. When the price floor is binding (i.e. set above the equilibrium price), it can lead to oversupply: more goods or services will be offered on the market than consumers are prepared to buy at that price. This can lead to surpluses, such as unsold stocks or, in the case of the labour market, unemployment.

Floor prices should therefore be used with caution and in the context of a thorough analysis of their potential effects. They can play an important role in income protection and the fight against poverty, but when they are badly adjusted, they can also cause undesirable market distortions.

This graph illustrates the impact of a minimum wage on the labour market. It shows two intersecting curves: the rising labour supply curve, which represents individuals wanting to work, and the falling labour demand curve, which represents companies looking to hire.

The minimum wage is indicated by a horizontal line running across the graph above the point where the supply and demand curves intersect. This minimum wage level is an example of a price floor. If this minimum wage is higher than the market equilibrium wage (the point where the two curves naturally cross), this means that it is binding. Excess labour, or unemployment, is represented by the horizontal gap between the quantity of labour offered and the quantity demanded at this minimum wage level. At a binding minimum wage, companies are only prepared to hire a smaller quantity of labour than individuals are prepared to offer at that wage. This creates a labour surplus, i.e. unemployment.

Analysis of this graph suggests that, although the minimum wage is designed to guarantee workers a decent income, it can also have the undesirable effect of creating unemployment, especially if the minimum wage is set without taking into account the specific situation of the labour market or productivity levels. Indeed, if the cost of labour becomes too high in relation to the value produced by that labour, companies may cut back on hiring, automate certain functions or relocate jobs to regions where costs are lower. In reality, the impact of a minimum wage on employment is the subject of lively debate among economists. Some argue that increases in the minimum wage can have little effect on employment, or can even stimulate the economy by increasing workers' purchasing power. Others stress the negative effects, particularly in sectors where labour is a significant cost and margins are low.

The effectiveness of a minimum wage as a policy therefore depends on many factors, such as the level of economic development, the structure of the labour market, and the flexibility of employers and employees. In some cases, additional measures may be needed to minimise the negative impact on employment, such as training to increase worker productivity or targeted aid for particularly hard-hit industries.

Minimum wage and unemployment

The elasticity of demand for labour is a measure of how responsive employers are to changes in the cost of labour. If the demand for labour is elastic, this means that even a small increase in the minimum wage can lead to a significant reduction in the number of jobs that employers are prepared to offer. This is particularly true in sectors where companies operate in highly competitive markets with fixed prices, where they cannot easily pass on additional costs to consumers without losing market share.

Low-skilled, labour-intensive sectors are often characterised by such competition. In these sectors, profit margins are generally low, and products or services are often standardised, which prevents companies from raising prices without risking losing customers to competitors. When the minimum wage is increased, businesses in these sectors may not be able to absorb the extra costs and may respond by reducing the number of hours offered or employing fewer workers. This can lead to a situation where the minimum wage causes increased unemployment, particularly among low-skilled workers, who are often least able to find other forms of employment due to their lack of specialist skills or advanced training. Increased unemployment among these workers can have profound social and economic consequences, such as increased poverty and reduced social mobility.

However, it is important to note that the link between the minimum wage and unemployment is not unequivocal. Some economists argue that increases in the minimum wage can stimulate aggregate demand by increasing the purchasing power of low-income workers, which in turn can stimulate employment and offset the effects of labour demand elasticity. Others suggest that moderate increases in the minimum wage can be absorbed by firms through productivity gains or a small increase in prices. It is therefore essential that policy decisions on the minimum wage take into account the specificities of the labour market and the economic conditions of each sector and region, and that they are accompanied by complementary policies, such as vocational training and education, to help low-skilled workers adapt to changes in the labour market.

Assessing the social impact and income redistribution associated with the introduction of a minimum wage is a complex issue that involves weighing the benefits against the potential drawbacks.

Benefits of a minimum wage:

• Increasing incomes: For workers who remain in employment, the minimum wage guarantees a basic income, which can help lift them out of poverty and improve their quality of life.
• Reducing inequality: By increasing the wages of low-income workers, the minimum wage can help reduce the income gap between low- and high-skilled workers.
• Stimulating aggregate demand: Low-income workers tend to spend a greater proportion of their income. Thus, increasing their wages can stimulate demand for goods and services, which can have a positive effect on the economy.

Disadvantages of the minimum wage:

• Job loss: For workers who lose their jobs as a result of the extra costs that employers have to bear, the consequences can be devastating, leading to financial hardship and increased reliance on welfare benefits.
• Barrier to entry into the labour market: Young workers and entrants to the labour market may find it more difficult to get a first job if employers are reluctant to hire at a higher minimum wage.
• Costs to small businesses: Small businesses, particularly those with low profit margins, may be particularly affected by the introduction of a minimum wage, which may lead them to reduce their workforce or, in extreme cases, close down.

To assess the net impact of the minimum wage policy, it is necessary to look at the proportion of workers who benefit from a pay rise compared to those who suffer a job loss or a reduction in working hours. This also means taking account of indirect costs, such as the impact on the prices of goods and services or changes in employers' hiring behaviour. The overall impact of minimum wages on income redistribution will depend on the economic and social structure of each country or region. In some cases, the benefits may outweigh the costs, especially if the minimum wage is complemented by other support measures such as vocational training, tax credits for low-income workers, and housing assistance programmes. A full assessment therefore requires not only an analysis of the economic data, but also consideration of the wider social consequences and society's values of equity and social justice.

In a competitive labour market, where many employers compete to hire workers, the introduction of a minimum wage can, according to the standard model, lead to an imbalance between labour supply and demand and potentially increase unemployment. However, if the labour market is far from perfectly competitive and is more akin to a monopsony - a situation where there is a single employer or a small number of employers who dominate the labour market - the impact of the minimum wage can be very different. In a monopsony, the employer has the power to set wages lower than would prevail in a competitive market because of the lack of competition for workers. Workers, having few or no alternative options, are forced to accept lower wages.

In this context, the introduction of a minimum wage could actually increase employment rather than reduce it. By setting a minimum wage, the government can force the monopolist to pay higher wages, which can bring the wage closer to the competitive level and encourage increased labour supply. Paradoxically, this can lead the monopsony operator to hire more workers because the minimum wage removes the advantage the employer had in hiring fewer workers at a wage below the competitive rate. Monopsony models are more complex and involve different assumptions from those of a perfectly competitive labour market. They require a nuanced understanding of market dynamics and how wages are set and negotiated. These models are studied in more advanced labour economics courses, where students learn to analyse labour markets in less idealised contexts and to grasp the political implications of these less standard situations.

The notion of the minimum wage runs through economic and social history as a mechanism for protecting workers against exploitation and precariousness. The earliest incarnations of wage controls can be traced back to sixteenth-century Britain, where specific towns introduced wage thresholds to curb employer abuse and guarantee a subsistence income for workers. These ad hoc measures reflected the social concerns of the time and marked an early recognition of the need to regulate employment relations.

At the end of the nineteenth century, as the world entered an era of rapid industrialisation, the issue of workers' pay became increasingly important. In New Zealand in 1894, and shortly afterwards in Australia, national minimum wage laws were introduced, setting legislative precedents that formally recognised the need for an income floor for workers. These policies were a response to the challenges posed by industrialisation, such as the rapid growth of cities, urbanisation, and the often difficult working conditions that ensued.

At the beginning of the twentieth century, the United Kingdom followed suit by introducing its own minimum wage legislation in 1909, targeting in particular sectors where insecurity and low pay were commonplace. This legislation marked a turning point in the way the government perceived its role in protecting the economic well-being of workers.

In the United States, the situation was evolving in a similar way. Although minimum wage measures had been introduced in some states as early as 1912, it was not until the Fair Labor Standards Act of 1938 that a federal minimum wage was established, before being extended in 1966 to include the majority of workers. This extension was in recognition of the fact that regulating workers' incomes was a national issue, transcending state borders.

In contrast to these examples, Switzerland is notable for not having a statutory minimum wage at national level. However, this does not mean that the issue of workers' pay is left to chance. Through collective agreements, minimum wages are negotiated between unions and employers, demonstrating a robust model of social dialogue. The 2012 popular initiative in Switzerland, which called for the introduction of a minimum wage of CHF 22 per hour, bears witness to the desire of certain social players to codify these protections in law, although the initiative was ultimately unsuccessful.

The historical and contemporary examples of the minimum wage reveal that, although the contexts and mechanisms may vary, the underlying principle remains constant: the need to ensure that workers receive a wage that allows them to live in dignity. Over the centuries, governments and societies have sought ways to balance market forces with social protection, striving to adapt minimum wage policies to the economic realities and values of their time.

The debate on the link between minimum wages and employment is one of the oldest and most persistent in labour economics. Economists have studied this question for a long time, but despite decades of research and analysis, there is still no clear empirical consensus. Studies produce divergent results, often due to differences in methodologies, time periods and locations studied, as well as the economic sectors concerned. On the one hand, some economists rely on the standard theoretical model of microeconomics, which predicts that an increase in the minimum wage above the market equilibrium level will reduce the demand for labour, leading to higher unemployment, particularly among low-skilled workers. They argue that employers will seek to cut costs by replacing labour with machines, relocating production, or simply hiring fewer workers.

However, other economists point to empirical studies which suggest that the effects of the minimum wage on employment are minimal or non-existent. These studies suggest that employers can absorb the additional costs of the minimum wage by increasing productivity, reducing staff turnover, slightly raising prices, or by slightly reducing profits. In addition, a higher minimum wage can stimulate aggregate demand by increasing the purchasing power of low-income workers. Differences in empirical results can also be attributed to the unique characteristics of each labour market. For example, in markets with a high demand for labour or in sectors where wages are already high, the impact of an increase in the minimum wage could be negligible. Conversely, in markets where labour is less in demand or in sectors that are highly cost-sensitive, such as fast food or retail, the impact could be more significant.

Finally, it should be noted that the effects of the minimum wage may vary not only between different regions and sectors, but also over time. Changing economic conditions, evolving technologies, demographic trends, and complementary government policies can all influence how changes in the minimum wage affect employment. Because of this complexity and diversity of outcomes, the debate on minimum wages and employment remains open, with valid arguments on both sides. Policymakers often have to navigate between these different points of view, seeking to find a balance that maximises social benefits while minimising potential negative effects on employment.

Taxation

The State's financial resources

To finance its many functions, the State does not rely solely on tax revenues or borrowing. It can also generate substantial income from the management and sale of its various assets. Historically and in today's context, the sale of public property represents a significant source of revenue for governments. Parcels of land, administrative buildings, sports or cultural facilities, even ports or airports, can be sold to the private sector. Such transfers are not trivial and must be carefully considered to ensure that they are beneficial to the community in the long term. For example, the sale of the UK's Royal Mail in 2013 was controversial, not least because of questions about the valuation of the business and the impact on the public service.

Tolls are another historic method of state funding. Notable examples include road tolls, such as those on the M6 motorway in the UK or the A1 motorway in France, which generate revenue for the maintenance and improvement of transport infrastructure. Similarly, rights of way on certain bridges or tunnels, such as the Golden Gate Bridge in San Francisco, contribute to the management and preservation of these iconic infrastructures.

Privatisation has been a major trend in recent decades, influenced by political and economic trends favouring the role of the market. Governments have sold off parts or all of public companies, as illustrated by the wave of privatisations in the 1980s under the Thatcher government in the UK, which saw the sale of companies such as British Telecom and British Gas. The aim of these privatisations was to reduce public debt, inject private sector efficiency into these companies and diversify the ownership of economic assets.

In addition, the state can grant concessions or licences to exploit services or resources. These range from broadcasting licences for television and radio stations to mining or oil concessions, which have been a mainstay of state financing in resource-rich countries. Norway, for example, used the revenue from its oil concessions to set up a sovereign wealth fund, now one of the largest in the world, guaranteeing long-term benefits for the population.

All these methods of state financing have their advantages and disadvantages, and the choice depends on many factors, including the political philosophy of the government in power, the state of the economy and the specific needs of society at a given time. The sale of assets can provide immediate financial relief, but can also raise concerns about the loss of control over assets previously held collectively. Tolls and concessions generate recurrent income, but can also be perceived as additional taxes by users. Privatisation can lead to increased efficiency and market-led innovation, but it can also lead to a reduction in the quality of services if profitability becomes the main concern of the new private owners. Ultimately, the management of public finances and the choice of financing methods remain a complex task that must be approached with careful attention to both short- and long-term consequences.

The state's main source of funding comes from its power to levy taxes on individuals and businesses. This power of fiscal coercion is a fundamental attribute of state sovereignty, enabling it to mobilise the resources needed to provide public goods and services, maintain order and security, and carry out infrastructure projects. Taxes take many forms, including but not limited to:

1. Income taxes: These are levied on individuals and companies. Personal income tax is often progressive, meaning that the rate of tax increases with the level of income. For companies, corporation tax is calculated on profits.
2. Consumption taxes: Value added tax (VAT) or sales tax is applied to goods and services. This tax is regressive, as it takes a larger proportion of the income of low-income households. # Property taxes: These are levied on real estate and are an important source of revenue for local governments.
3. Customs duties: Levied on imported goods, they have a dual function: to generate revenue and to protect domestic industries from foreign competition.
4. Social contributions: Intended to finance social security systems, these contributions are often levied on employees' wages and employers.

Governments may also levy charges for the use of natural resources (such as oil, gas and minerals) or for issuing licences and permits in certain regulated areas (such as broadcasting or fishing). Taxes are essential not only for financing public expenditure but also for implementing economic and social policies. For example, taxes can be used to redistribute wealth, encourage or discourage certain economic behaviour, and stabilise the economy. However, the introduction of these levies must be carefully managed so as not to stifle economic activity or unfairly increase the burden on certain sections of the population.

Historically, the evolution of tax systems has reflected changes in the balance between the State's financing needs and society's ability to pay. For example, the tax reform in the United States in 1913, which introduced the federal income tax, represented a major change in tax policy, recognising the need for a more stable and equitable source of revenue to fund growing government activities. From a contemporary perspective, the design and administration of tax systems are major governance issues, with a delicate balance to be maintained between economic efficiency, social equity and political acceptability.

In addition to taxes, the state finances its activities by other means, including borrowing and transfers, each with its own dynamics and implications.

1. Government borrowing: Governments borrow money to finance expenditure that exceeds their tax revenues. This debt is often incurred by issuing government bonds, which are financial instruments that promise to repay the amount borrowed with interest at a specified future date. These bonds can be purchased by individuals, companies, banks and even other countries. Borrowing has a number of advantages, including the ability to finance major infrastructure projects, stimulate the economy in times of slowdown, and meet urgent needs without immediately raising taxes. However, excessive debt can lead to long-term problems, particularly in terms of interest charges and fiscal sustainability.
2. Transfers: Transfers are another source of funding for government activity. They can take the form of financial aid from other states or international organisations, such as grants, donations or development aid. Transfers can also come from intergovernmental funds within the same country, where the central government redistributes resources to local or regional governments. This form of funding is particularly important for regions or countries that do not have sufficient resources of their own to finance their activities, or for developing countries that may be dependent on foreign aid for their development projects.

Over-dependence on borrowing can lead to unsustainable debt, while dependence on transfers can compromise political and economic autonomy. For example, the sovereign debt crisis in the eurozone has highlighted the challenges associated with high public debt, where countries such as Greece have had to implement severe austerity measures in response to conditions imposed by international creditors.

Both of these forms of financing underline the need for governments to maintain a careful balance between different sources of revenue. A judicious mix of taxes, borrowing and transfers can provide the flexibility to meet public needs without compromising the long-term financial health of the state.

Taxes

Tax is the main source of revenue for most countries and is characterised by the fact that it is levied without any direct consideration. This means that, unlike specific services or goods purchased by a consumer, taxpayers do not receive a specific service or good in exchange for the tax they pay.

Taxes are used to fund a wide range of public services and state functions that benefit society as a whole, rather than specific individuals. These include:

• Public Services and Infrastructure: Taxes fund essential services such as public health, education, security (police and military), infrastructure maintenance (roads, bridges, water and electricity systems), and social services. * Redistribution of Wealth: Taxes also enable wealth to be redistributed within society, notably through social security programmes, unemployment benefits, retirement pensions, and aid for people on low incomes or with disabilities.
• Economic Stability and Growth: Tax revenues help the State to invest in key sectors to stimulate economic growth and to intervene in the event of economic fluctuations, for example by increasing spending in times of recession to support demand. Investment in the Future: Taxes also fund research and development projects, environmental initiatives and educational programmes, which are essential for the long-term development of a society.

The absence of direct consideration for taxes is what distinguishes them from tariffs or charges, where payments are directly linked to the provision of a specific service or good. For example, road tolls or university tuition fees are payments for specific services, whereas taxes are collected for the common good and benefit society as a whole.

However, the nature of taxation without direct compensation raises challenges in terms of perception and acceptability. Citizens and businesses may be reluctant to pay taxes if they do not receive direct benefits or if they feel that the funds are not used efficiently. This makes transparency, accountability and efficiency in the management of tax revenues crucial to maintaining public confidence and the legitimacy of the state.

The distinction between direct and indirect taxes is a key element of modern taxation, reflecting different methods of raising tax revenue.

1. Direct taxes: These are tax levies that depend on the financial situation of the individual or entity (natural or legal person). Direct taxes are generally progressive, which means that the tax rate increases with the taxpayer's ability to pay. Here are some examples of direct taxes:
   • Income tax: levied directly on the income of individuals or companies. For individuals, this tax may take into account various factors such as total income, family situation and allowable deductions.
   • Corporation tax: Taxed on company profits.
   • Property tax: Based on the value of property owned. Direct taxes are often seen as fairer because they are adjusted according to people's ability to pay. However, they can also be more complex to administer and collect.
2. Indirect taxes: These taxes are levied on market transactions and do not depend on the individual characteristics of the person paying the tax, which makes them more anonymous. Indirect taxes are generally regressive, as they take a larger proportion of the income of low-income households. Examples of indirect taxes include:
   • Value added tax (VAT) or sales tax: Applied to the majority of goods and services.
   • Excise duties: Imposed on certain specific products such as alcohol, tobacco, and fuel.
   • Customs duties: Levied on imported goods. Indirect taxes are generally easier to collect and less likely to be avoided than direct taxes. However, they can fall disproportionately on low-income consumers, as these taxes are applied uniformly regardless of income.

In practice, most tax systems use a combination of direct and indirect taxes to finance public spending. This combination aims to balance the objectives of efficient revenue collection, tax fairness and economic stability.

Taxation can be divided into two broad categories depending on how it is calculated and collected: ad valorem and unitary (or specific). Each of these methods has its own characteristics and applications.

1. Ad Valorem taxation: In this type of taxation, the amount of tax is proportional to the value of the good or service being taxed. The tax rate is expressed as a percentage, and the taxable base is the monetary value of the item being taxed.
   • Example of VAT: Value Added Tax (VAT) is a typical example of an ad valorem tax. VAT is calculated as a percentage of the value of the goods or services sold. For example, if a product costs 100 euros and VAT is 20%, the consumer will pay 120 euros (100 euros + 20% VAT). Ad valorem taxes are widely used because they are flexible and adapt to the value of transactions. They are also relatively easy for taxpayers to administer and understand.
2. Unitary (or Specific) Taxation: With this method, the amount of tax is fixed per physical unit of property taxed, regardless of its value. The rate is therefore expressed in monetary units per physical unit (e.g. per litre, per kilogramme, etc.)
   • Example of petrol tax: A classic example is petrol tax. If the tax is 73 cents per litre of unleaded petrol, this means that for each litre sold, 73 cents will be added to the price, irrespective of the basic price of the petrol. Unit taxes are often used for products where it is more appropriate to tax quantity rather than value, as in the case of tobacco products, alcohol or fuels. These taxes may have specific objectives, such as discouraging the consumption of products that are harmful to health or the environment.

Each of these methods has its advantages and disadvantages. Ad valorem taxes adjust automatically to price fluctuations and can be fairer in terms of ability to pay. Unit taxes, on the other hand, are simple to calculate and collect, and can be more effective in achieving certain policy objectives, such as reducing consumption of certain products. The choice between these methods depends on the specific tax policy objectives and the nature of the goods and services concerned.

Value Added Tax (VAT) is a major source of tax revenue for many governments, including the Swiss Confederation. The fact that VAT receipts account for a substantial proportion of the Confederation's resources underlines its importance in the country's tax structure.

In Switzerland, VAT is levied at different rates depending on the nature of the goods and services:

• Standard rate of 8%: This rate applies to the majority of goods and services. It is a relatively moderate rate compared with those applied in other European countries, where the VAT rate can exceed 20%. The standard rate is designed to cover a wide range of products and services, providing a significant and regular source of tax revenue for the government.
• 2.5% reduced rate for food, sport and culture: This reduced rate is applied to goods and services considered essential or beneficial to society. The aim of this reduced rate is to make these goods and services more accessible to the population as a whole, in recognition of their importance to people's daily well-being. Food, for example, is taxed at this reduced rate to ease the financial burden on consumers, particularly low-income households.

The structure of VAT in Switzerland reflects a balance between the need to generate revenue for the state and the desire to maintain the affordability of essential goods. This stratified approach, with different VAT rates, is a common feature of VAT systems in many countries, allowing flexibility in the pursuit of fiscal and social objectives.

The significant reliance on VAT for government revenues also demonstrates the robustness of consumption as a tax base. However, it also underlines the importance of an efficient tax administration to collect this revenue and of a balanced tax policy to ensure that the tax burden is not excessively borne by consumption, especially by the most vulnerable sections of society.

Indirect taxation

Indirect taxes reduce incentives to produce and consume, because the price paid by the consumer increases and the price received by the producer falls. The difference between the two is the amount of tax that is collected by the government ($p^{d}-p^{s}=t$).

Indirect taxes, such as value added tax (VAT) or excise duties, have an impact on incentives to produce and consume by altering the prices paid by consumers and received by producers. When a tax is imposed on a good or service, the price paid by the consumer (noted $p^{d}$ in the equation) increases, while the price received by the producer (noted $p^{s}$ in the equation) decreases. The difference between these two prices is the amount of tax ($t$), which is collected by the government.

For the consumer, the tax increases the cost of purchase, which may reduce demand for the good or service. For the producer, the tax reduces the income he receives from the sale, which may reduce the incentive to produce or offer the good or service. This can lead to a loss of economic efficiency, as the tax creates a gap between the price consumers are prepared to pay and the price producers are prepared to accept. This loss of efficiency is often represented graphically in economic models by a loss of surplus, which is the combined loss of consumer and producer surplus due to the tax. In theory, this loss represents a reduction in the overall efficiency of the market: fewer transactions occur than in the absence of the tax, and resources are not used as efficiently as possible.

However, it is important to note that indirect taxes are a key tool for governments to generate the revenue needed to fund public services and infrastructure. Furthermore, in some cases, indirect taxes can be used for specific policy objectives, such as discouraging the consumption of products that are harmful to health (such as tobacco and alcohol) or the environment (such as fossil fuels). So while indirect taxes can reduce incentives to produce and consume, potentially reducing economic efficiency, they can also be justified by wider public policy considerations.

When a good is taxed, the impact of that tax on the market depends on the price elasticity of supply and demand. Price elasticity measures the sensitivity of quantities offered or demanded to a change in price. This sensitivity plays a key role in determining how the tax burden is distributed between consumers and producers.

1. Reduction in quantities traded: The introduction of a tax on a good or service generally increases the price that consumers have to pay and reduces the price that producers receive, leading to a reduction in the quantities traded on the market compared with an equilibrium situation without tax. This results in a loss of surplus for consumers and producers, and a reduction in the overall efficiency of the market.
2. Impact of the tax: The impact, or burden, of the tax depends on the relative elasticity of supply and demand.
   • If demand is relatively inelastic (i.e. consumers do not reduce their quantity demanded much even when the price increases), then consumers will bear a greater share of the burden of the tax. Conversely, if supply is relatively inelastic (i.e. producers do not reduce their quantity offered very much even when the price they receive decreases), then producers will bear a greater share of the burden of the tax. In this case, producers continue to supply the product despite the drop in the net price they receive.

The way in which the tax burden is distributed has important implications for tax policies and their impact on different groups within society. For example, a tax on a staple good, for which demand is generally inelastic, may weigh more heavily on consumers, including low-income households. On the other hand, a tax on a luxury good, for which demand is more elastic, could have a greater impact on producers.

This distribution of tax incidence is a key element to consider when designing fair and effective tax policies. Decision-makers need to assess not only the revenue potential of taxes, but also their effects on consumers and producers and, by extension, on the economy as a whole.

Taxes on consumers versus taxes on producers

When it comes to the economic impact of taxes, whether the tax is technically levied on consumers or on producers does not fundamentally affect the distribution of its burden, nor the equilibrium quantity in the market, nor the total amount of tax revenue. This is due to the so-called tax incidence, which depends on the relative elasticity of supply and demand rather than on whom the tax is officially levied.

1. Independence of the tax incidence from the legal taxpayer: Whether the tax is imposed on consumers or producers, it will result in an increase in the price paid by consumers and a reduction in the price received by producers. In both cases, the market adjusts until a new equilibrium price is reached where the quantity demanded equals the quantity offered. The key difference is in the way the market price is modified to absorb the tax.
2. Equilibrium quantity and tax revenue: The equilibrium quantity on the market after the imposition of a tax will be the same whether the tax is levied on consumers or on producers. Similarly, the tax revenue generated by the tax will be identical in both cases. What changes is the way in which the tax burden is distributed between consumers and producers.
3. Role of elasticity: The decisive factor in the distribution of the tax burden is the elasticity of supply and demand. If demand is inelastic in relation to supply, consumers will bear a greater share of the tax burden, regardless of the portion on which the tax is technically imposed. Conversely, if supply is inelastic in relation to demand, producers will bear a greater share of the burden.

The economic impact of a tax therefore depends on the way it modifies incentives and behaviour in the market, and not on the part on which it is officially imposed. This distinction is crucial to understanding the real effects of tax policies and to designing taxes that achieve the desired objectives fairly and efficiently.

Tax on consumers

When a tax is imposed directly on consumers, it has a significant impact on the economy and the behaviour of market players. Let's take the example of a tax on luxury goods. Suppose the government decides to impose an additional tax on these products, thereby raising the price that consumers have to pay. In this scenario, the purchase price of a luxury watch, for example, would increase by the amount of the tax. This increase in price would affect demand for these watches. If consumers see the watch as a luxury item they can do without, they may reduce their purchase or look for cheaper alternatives, reflecting elastic demand. However, the impact of this tax is not limited to consumers. Producers of luxury watches would also feel the effects of this tax. As demand falls, they may be forced to cut prices or reduce production. In other words, although the tax is levied on consumers, part of its economic burden is transferred to producers.

How this tax burden is distributed between consumers and producers depends largely on the elasticity of demand and supply. If consumers have few alternatives and consider luxury watches to be essential, they may continue to buy despite rising prices, thereby absorbing a greater proportion of the tax burden. Conversely, if consumers are price-sensitive and reduce their purchases considerably, producers will have to absorb a greater proportion of the tax in the form of reduced revenue. The tax revenue generated by this tax would depend on the number of transactions that take place after it is imposed. If the tax leads to a significant reduction in sales, the expected revenue may not be achieved. This illustrates a common dilemma in tax policy: finding the balance between imposing taxes to generate revenue and avoiding discouraging economic activity.

Historically, many governments have used taxes on consumer products to generate revenue. For example, the tea tax that led to the famous Boston Tea Party was a tax imposed by the British government on tea consumers in the American colonies. This tax ultimately had a major political impact, contributing to the discontent that led to the American Revolution.

Taxes imposed on consumers may seem to target those who buy products directly, but their effects ripple throughout the economy, affecting both demand and supply, and influencing the decisions of producers and consumers. The way these taxes are structured and their level can have important consequences for market dynamics and tax policy objectives.

A €0.50 tax on consumers.

The graph shown here illustrates the impact of a tax on ice cream consumption. Initially, the market stabilises at a point where the price is 3.00 euros and the quantities of ice cream traded correspond to the equilibrium between supply and demand. The introduction of a tax of €0.50 per unit of ice cream for consumers leads to a transformation in purchasing behaviour: the demand curve shifts downwards by an amount equivalent to the tax, illustrating a reduction in the quantity of ice cream that consumers are prepared to buy at each price level.

As a result of this taxation, the price consumers pay for ice cream increases to €3.30, incorporating the €0.50 tax. However, the price producers actually receive falls to €2.80, as the tax levied on consumers leads them to reduce their demand. This divergence between the price paid by consumers and the price received by producers is the concrete manifestation of the tax burden shared between the two parties.

The market equilibrium then shifts to a point where fewer ice creams are traded than before, a direct reflection of the reduction in demand due to higher prices for consumers. This market adjustment is not simply a question of price; it is also symptomatic of a loss of market efficiency, where consumers and producers see their economic surplus diminish as a result of the tax.

The exact impact of this tax on the market does not intrinsically depend on which party pays it to the government. Whether it is consumers or producers who are designated as responsible for paying the tax, the effect on the selling price and the buying price is the same, once market reactions are taken into account. What matters is not who remits the tax money to the State, but rather how the elasticity of supply and demand determines the effective distribution of this tax burden.

This distribution is influenced by the sensitivity of consumers to price changes (elasticity of demand) and by the responsiveness of producers to changes in income (elasticity of supply). If consumers have few alternative options and continue to buy ice cream despite rising prices, they will bear a large proportion of the tax. Conversely, if producers cannot reduce their cost of production or increase their selling price, they will absorb a larger part of the burden.

This example demonstrates the importance of economic analysis in understanding the implications of tax policies. A tax on consumers may seem simple on the surface, but it creates ripples that affect the whole market, influencing both consumer welfare and the financial health of producers, while changing the overall dynamics of the economy.

Taxes on producers

When a tax is imposed on producers, it is designed to be levied directly on business income from the sale of goods or services. This can be seen as an additional cost to production. For example, if a government introduces a tax on each kilogram of coffee produced, coffee producers will see their costs increase by the amount of this tax.

The producers' immediate response might be to try to pass this tax on to consumers in the form of higher prices. If the market is competitive, producers may find it difficult to do this fully, as they risk losing market share to competitors or substitute products. The ability to transfer the burden of the tax depends very much on the elasticity of consumer demand. If demand is inelastic, consumers will continue to buy the product despite the price increase, and the majority of the tax burden will be borne by them. If demand is elastic, consumers will reduce their purchases, and producers will have to absorb a greater proportion of the tax burden.

The tax on producers also has wider consequences for the economy. It can discourage investment in specific sectors, reduce the incentive to innovate or improve productivity if profit margins are eroded by the tax. In the long term, this can lead to a reduction in supply, an increase in prices, and potentially a less dynamic market.

In economic history, taxes on producers have often been used to protect infant industries or to encourage or discourage certain industrial practices. However, they have sometimes been criticised for their impact on consumer prices and for distorting economic incentives. For example, taxes on cigarettes aim to reduce consumption by increasing the cost of production, which translates into higher prices for consumers. However, such taxes can also encourage the black market if legal prices become too high.

Policymakers must therefore carefully assess the economic impact of taxes on producers, taking into account the likely reaction of producers and consumers, as well as the potential effects on overall output, employment and economic growth. This is a delicate balancing act that requires an in-depth understanding of the specific market dynamics of each sector.

A €0.50 tax on producers.

In the graph shown, we observe the effects of a tax imposed on ice-cream producers. Prior to the imposition of the tax, the market reaches an equilibrium point where the price of ice cream is set at €3.00, and a certain quantity is traded between producers and consumers. This equilibrium point reflects a consensus between the quantity that producers are prepared to offer and the quantity that consumers are prepared to buy at this price.

The introduction of a €0.50 tax on producers changes this situation. This tax represents an additional cost for each unit of ice cream produced, resulting in an upward shift in the supply curve. In practical terms, this means that to continue offering the same quantity of ice cream, producers need to receive a higher price to offset the cost of the tax. In response, the supply curve shifts to a new position, indicating a higher price needed to balance the market.

As a result, the price paid by consumers for ice cream rises to €3.30, while producers receive only €2.80 after the tax. This difference of €0.50 is exactly the amount of tax that the government levies, illustrating the fiscal impact of the tax. Despite the fact that the tax is imposed directly on producers, the economic burden of the tax is shared with consumers, who end up paying a higher price.

The market equilibrium readjusts to a level where less ice cream is traded than before, a direct effect of the reduction in demand induced by the price increase. This reduction in the quantity traded indicates a loss of market efficiency, as the tax discourages transactions that would otherwise have taken place. The market no longer achieves the optimal level of exchange that would maximise the welfare of consumers and producers.

The impact of the tax on producers goes beyond the simple additional cost per unit produced; it has repercussions for the market as a whole. Producers may be forced to reduce production in response to falling demand, which may lead to a reduction in employment in the ice cream sector or discourage investment in new technology or production capacity.

In short, the graph shows that taxes on producers affect consumer prices and disrupt the natural balance of the market. These changes are not just figures on balance sheets; they reflect changes in consumer behaviour and production strategies, and have wider implications for the economy as a whole. Policymakers therefore need to consider these effects carefully when designing tax policies, balancing the need for public revenue with the objectives of maintaining a dynamic and efficient market.

Taxation: who pays? The role of price elasticities

The distribution of the tax burden between consumers and producers is a central issue in tax economics. It does not depend on the agent on whom the tax is legally imposed. The essence of this allocation is based on the concepts of price elasticity of supply and demand.

The price elasticity of demand measures the sensitivity of the quantity demanded to a variation in price. If demand is inelastic, an increase in price due to a tax will lead to only a slight decrease in the quantity demanded. Consumers continue to buy almost the same quantity of the good despite the price increase. In this case, consumers absorb a large part of the tax burden because they do not significantly reduce their consumption in response to the price rise. Conversely, the price elasticity of supply measures the responsiveness of the quantity offered to a change in price. If supply is inelastic, producers cannot easily adjust the quantity they produce in response to a price change. When the tax is imposed, they cannot significantly reduce their production, and therefore bear a greater share of the tax burden, often receiving less revenue for each unit sold.

When tax is imposed, the market price adjusts to reflect this tax burden. If the tax is officially paid by consumers, the market price rises. If the tax is paid by producers, the price they receive falls. But regardless of these initial adjustments, the final tax burden will depend on how consumers and producers adjust their behaviour in response to these new prices. In economic reality, the distinction between "who pays the tax" and "who bears the burden of the tax" is crucial. Taxes on cigarettes, for example, are often passed on to consumers in the form of higher prices. However, if consumers significantly reduce their consumption in response to these higher prices (demonstrating a high elasticity of demand), producers may be forced to lower prices to maintain their sales volumes, thereby absorbing more of the tax burden.

The price elasticity of an economic agent - whether a consumer or a producer - reflects its ability to adapt to price changes. Elasticity is an indicator of the flexibility of the response in terms of quantity demanded or offered following a price change. When an agent has a low price elasticity, this means that there is little change in the quantity demanded or offered even when the price changes significantly. In the case of consumers, this may be due to the absence of close substitutes for the good or service being taxed, or because the good is considered a necessity. For producers, it could be due to production constraints that prevent them from adjusting quickly to price changes.

Let's take a concrete example. In the case of petrol, consumers may have low short-term price elasticity because they cannot easily change their travel habits or the type of vehicle they use in response to an increase in fuel prices. As a result, if a tax is imposed on petrol, consumers will continue to buy almost the same amount of petrol, and the burden of the tax will largely be passed on to them in the form of higher prices at the pump. On the other hand, if producers of a good have little ability to change their volume of production because of high fixed costs or complex production processes, they have a low elasticity of supply. If a tax is imposed on this good, they will not be able to significantly reduce production to maintain their prices, and they will absorb a greater proportion of the tax burden, resulting in a reduction in their net income.

In extreme cases of elasticity, the impact of the tax may be borne entirely by one of the economic agents, either consumers or producers.

1. Perfectly inelastic demand or perfectly elastic supply: If demand is perfectly inelastic, this means that the quantity demanded by consumers does not change, regardless of the price change. Consumers will therefore pay any price to obtain the same quantity of the good. In this situation, if a tax is imposed, consumers will have no choice but to pay the higher price including the tax, because their need or dependence on the product does not allow them to reduce their consumption. As a result, the total burden of the tax falls on consumers. If supply is perfectly elastic, producers are prepared to offer any quantity of the good at the same price. If a tax is imposed, they can simply increase their production to maintain their level of income, which means that the price for consumers remains unchanged, and producers do not suffer any burden from the tax. However, this situation is theoretical because, in practice, producers have production capacities and variable costs that prevent perfectly elastic supply.
2. Perfectly elastic demand or perfectly inelastic supply: When demand is perfectly elastic, consumers are prepared to buy the entire quantity of the good only at a specific price and are not prepared to pay more. If a tax is added and producers try to pass this tax on to consumers by raising prices, consumers will stop buying the product altogether. As a result, the burden of the tax must be fully absorbed by producers for the product to be sold. On the other hand, if supply is perfectly inelastic, producers will supply a fixed quantity of the good, regardless of the price they receive. So any tax imposed will not change the quantity supplied, and producers cannot reduce their output in response to a fall in price. As a result, they bear the full burden of the tax.

These extreme cases serve as important theoretical illustrations for understanding tax incidence. They show how the flexibility or inflexibility of consumers and producers in adapting to price changes determines who bears the economic cost of a tax. Although such perfectly elastic or inelastic situations are rare in reality, they offer clear insights into the dynamics of tax pass-through in various market scenarios.

Elastic supply and inelastic demand

In a scenario where supply is elastic and demand inelastic, the dynamics of the distribution of the tax burden between consumers and producers are clear:

1. Inelastic demand: When demand is inelastic, consumers do not reduce their quantity demanded very much in response to a price increase. The goods or services in question are often essential or have no close substitutes, such as vital medicines or fuel. In this case, even if the price rises as a result of a tax, consumers will continue to buy almost the same quantity of these goods. In this way, the burden of the tax is borne mainly by consumers, as they have little scope for substitution or for adjusting their consumption.
2. Elastic supply: Elasticity of supply means that producers are sensitive to changes in price in their production decisions. If producers can easily increase or decrease their production in response to price changes, they have an elastic supply. In a tax environment, if producers can easily adjust their production and costs can be reduced or production can be increased without significant additional costs, they will be able to avoid bearing a large part of the tax burden. They have the capacity to absorb part of the tax without significantly reducing their profit margin, or to pass part of it on to consumers.

Combining these two concepts, in a market where supply is elastic and demand inelastic, most of the tax burden shifts to consumers. Producers can adjust their output to avoid incurring the full tax, while consumers, with little capacity for adjustment, will end up paying the majority of the tax in the form of higher prices.

To illustrate this with a concrete example, let's look at the petrol market. Usually, consumers have a relatively inelastic demand for petrol in the short term; they cannot easily change their driving habits or switch to energy alternatives overnight. Consequently, even if a tax is imposed on petrol, consumers will probably be obliged to pay that tax. On the other hand, while oil producers can adjust their production relatively easily in response to price fluctuations, they have some flexibility to avoid absorbing the entire tax.

So, in this market, a tax on petrol would largely be passed on to consumers, resulting in higher prices at the pump, while producers could avoid cutting production or suffering a significant drop in revenue. This demonstrates the importance of elasticities in understanding who ultimately pays for a tax imposed on a product or service.

This graph illustrates the effect of a tax on a market where supply is more elastic than demand. Three main points are highlighted in the annotation to the graph:

1. Elasticity of supply relative to demand: The supply curve, which is more vertical, indicates that supply is less sensitive to price change than demand; i.e. demand is more inelastic than supply. This suggests that consumers are unlikely to adjust their quantity demanded in response to a price change, whereas producers are prepared to adjust their quantity supplied more significantly if prices change.
2. Impact of the tax on consumers: As the upper part of the vertical arrow indicates, the price paid by consumers after the tax is significantly higher than the equilibrium price without the tax. This suggests that the burden of the tax is borne mainly by consumers. They pay most of the tax in the form of higher prices, because their inelastic demand leads them to absorb most of the additional costs.
3. Impact on producers: The bottom of the vertical arrow shows that the price received by producers after the tax is slightly lower than the equilibrium price without tax. This means that although producers bear part of the burden of the tax, the impact on them is less significant than on consumers. The greater elasticity of supply allows producers to adjust their production to minimise the impact of the tax on their income.

In summary, this graph shows that when demand is inelastic and supply is elastic, consumers end up bearing a greater proportion of the tax. Producers, who can adjust their production more easily in response to price variations due to the tax, are less affected. This highlights the importance of the elasticity of demand and supply in determining the impact of taxation and in understanding how taxes influence the behaviour of market players and the distribution of costs between them.

Inelastic supply and elastic demand

When supply is inelastic and demand is elastic, we find ourselves in a situation where the roles are reversed compared to the previous example. Here, producers have little ability to change the quantity of goods they offer in response to a price change, whereas consumers are very sensitive to price changes and are prepared to adjust their demand, or even to turn to substitutes if the price rises.

1. Inelastic supply: This means that producers cannot easily increase their output in response to a price rise, perhaps because of capacity constraints, high fixed costs or the unavailability of additional resources. In the case of a tax, producers cannot reduce their cost of production or increase their output sufficiently to offset the cost of the tax, so they have to absorb a large part of the tax burden. The price they receive for each unit sold falls, reducing their profit. #Elastic demand: Consumers are prepared to change significantly the quantity they buy in response to a price change. If the price of a good rises because of a tax imposed on producers and passed on in prices, consumers will reduce their consumption of that good, look for cheaper alternatives or abandon the purchase. In this way, consumers only bear a small part of the tax burden because they avoid paying higher prices by reducing their demand. #Incidence of the tax: In such a market, most of the burden of the tax falls on producers, who have to lower their prices to maintain their sales, because consumers react strongly to price increases. Producers, unable to increase production or find lower costs, suffer a reduction in their net income.

To illustrate, let's consider a market for agricultural products such as wheat, where production techniques and the amount of land available are fixed in the short term, making supply inelastic. If the government imposes a tax on wheat, farmers cannot immediately increase their production to compensate for the tax. On the other hand, if consumers can easily switch to other cereals or food sources when the price of wheat rises, their demand is elastic. So a tax on wheat would be largely absorbed by farmers, and consumers would change their consumption to minimise the impact of the tax on them.

In short, in a market where supply is inelastic and demand is elastic, producers bear the main burden of taxes because they cannot adjust their supply in response to price changes, while consumers can easily reduce their demand or find substitutes, enabling them to avoid paying the tax.

The graph presents a market where a tax is imposed and shows how the impact of this tax is distributed between consumers and producers, according to the elasticity of demand in relation to that of supply.

1. Elasticity of demand in relation to supply: The graph shows that demand is more elastic than supply. This means that consumers are relatively sensitive to price changes and are prepared to alter the quantity demanded considerably in response to a price change. On the other hand, supply is less sensitive to price changes, suggesting that producers are unable or unwilling to adjust their quantity offered significantly when prices change.
2. Incidence of tax on producers: The tax leads to a reduction in the price received by producers. As the supply curve is relatively inelastic, producers cannot easily reduce their production, and so they absorb a large part of the burden of the tax. This situation is represented by the difference between the price without tax and the price received by producers after the tax. The price received by producers falls, which can lead to lower revenues and, potentially, profits.
3. Impact on consumers: Although demand is more elastic, consumers still experience an increase in the price of ice cream, which is illustrated by the difference between the price without tax and the price paid by consumers. However, because demand is elastic, consumers will reduce their consumption more than producers reduce their production, and so the tax burden borne by consumers is less than that borne by producers. The graph therefore shows that when demand is elastic and supply inelastic, producers bear a greater proportion of the tax incidence. They are forced to lower the price they receive in order to remain competitive, despite the additional burden of the tax. Consumers, faced with a rise in prices, can more easily turn away from the taxed product and reduce their consumption, which protects them from a large part of the tax impact. This example illustrates how the flexibility or rigidity of market players in response to price changes influences the distribution of tax incidence between producers and consumers.

Determining equilibrium in the presence of a tax

In a market with a tax, equilibrium is reached when the quantity demanded is equal to the quantity supplied, taking into account the impact of the tax on the prices paid by consumers and received by producers. The following equations illustrate this concept.

$q^{d}(p^{d})=q^{s}(p^{s})$:

• $q^{d}$ is the quantity demanded by consumers at price $p^{d}$, the price after tax.
• $q^{s}$ is the quantity offered by producers at price $p^{s}$, the price before tax.

This equation states that market equilibrium is reached when the quantity consumers wish to buy at the price they pay (including tax) is equal to the quantity producers wish to sell at the price they receive (after deducting tax).

$p^{d}-p^{s}=t$:

• $p^{d}$ is the price paid by consumers.
• $p^{s}$ is the price received by producers.
• $t$ is the amount of tax per unit sold.

This equation shows that the difference between the price paid by consumers and the price received by producers is equal to the amount of tax. In other words, the tax creates a gap between the purchase price and the sale price, and this gap represents the tax collected by the state.

In a tax-free market, $p^{d}$ and $p^{s}$ would be equal, and equilibrium would simply be determined by the equality between quantity offered and quantity demanded. However, the introduction of a tax changes the prices received by both parties and, consequently, affects the quantities traded. Market agents react to these new prices: consumers by adjusting their demand and producers by adjusting their supply.

To determine the exact equilibrium in the presence of a tax, economists analyse how the tax affects the elasticity of demand and supply and use these equations to calculate the new equilibrium prices and the quantities traded. This is a fundamental exercise in microeconomics that helps to understand the consequences of tax policies and to design tax systems that achieve the desired revenue objectives with the least possible distortion of the market.

When a unitary tax is introduced in a market, whether it is buyers or sellers who are responsible for paying that tax, it affects the prices and quantities traded in that market. Here's how the tax translates into market equilibrium equations:

If the tax (unit t) is paid by buyers: In this case, the price paid by buyers ( $p^{d}$ ) is the price at which sellers are willing to sell ( $p^{s}$ ) plus the amount of the tax ( $t$ ). Market equilibrium is reached when the quantity that buyers are willing to buy at this higher price is equal to the quantity that sellers are willing to offer at the price without the tax. The corresponding equations are :

$p^{d}=p^{s}+t$ $q^{d}(p^{s}+t)=q^{s}(p^{s})$

Here, $p^{s}$ is the equilibrium market price without tax.

If the tax (unit t) is paid by sellers: When sellers pay the tax, the price they receive ( $p^{s}$ ) is the price paid by buyers ( $p^{d}$ ) minus the amount of the tax ( $t$ ). Equilibrium in the market is reached when the quantity that sellers are willing to offer at this price after tax is equal to the quantity that buyers are willing to buy at the full price. The equations for this situation are:

$p^{s}=p^{d}-t$ $q^{d}(p^{d})=q^{s}(p^{d}-t)$

In this case, $p^{d}$ is the equilibrium market price that buyers pay, including tax.

In both scenarios, the tax creates a gap between the price paid by consumers and the price received by producers. This gap is equivalent to the amount of the tax. The impact on the market will depend on the elasticity of demand and supply. If demand is inelastic, consumers will end up paying most of the tax. If supply is inelastic, producers will bear the main burden of the tax. The market equilibrium reflects these adjustments in the quantities traded and the prices paid following the introduction of the tax.

The linear demand function is given by: $q^{d}(p^{d})=a-bp^{d}$; where $a$ and $b$ are parameters, $q^{d}$ is the quantity demanded and $p^{d}$ is the price paid by demanders (consumers).

The linear supply function is $q^{s}(p^{s})=c+dp^{s}$; where $c$ and $d$ are parameters, $q^{s}$ is the quantity offered and $p^{s}$ is the price received by the offerers (producers).

The tax is represented by the difference between the price paid by consumers and the price received by producers: $p^{d}-p^{s}=t$.

Under case (1), where the tax is paid by buyers, we have the following equilibrium equation: $a-b(p^{s}+t)=c+dp^{s}$.

Solving for $p^{s}$, the equilibrium price without tax, we obtain: $p^{s}*={\frac {a-c-bt}{d+b}}$.

The equilibrium price with tax paid by consumers, $p^{d}$, would be: $p^{d}=p^{s}+t={\frac {a-c-bt}{d+b}}+t$.

And so the final equilibrium price paid by consumers, taking into account the tax, is: $p^{d}*={\frac {a-c+dt}{d+b}}$.

These equations allow us to determine the equilibrium prices and quantities traded in the market after the imposition of a tax when the demand and supply functions are linear. They show how the tax shifts the market equilibrium by affecting prices paid and received, and how demand and supply parameters influence the impact of the tax.

Summary

Price ceilings and price floors are two types of control that governments can impose on markets to influence market prices and achieve specific social or economic objectives.

Price ceiling: This is a maximum price set by the government for certain goods or services. The aim is generally to make goods more accessible to consumers, particularly for basic necessities. A classic example is rent control, where the government imposes a maximum price on rents to make them affordable. However, price ceilings can lead to shortages if the price is set below the equilibrium market price, because at this price level the quantity demanded exceeds the quantity supplied.

Price floor: Conversely, a price floor is a minimum price at which a good or service can be sold. This is often used to guarantee producers a minimum income, as in the case of the minimum wage. When the floor price is above the equilibrium market price, this can lead to surpluses, in particular an excess of supply over demand, as can be the case with unemployment when the minimum wage is too high.

Impact of taxes: Taxes imposed on markets, whether on consumers (consumption taxes) or on producers (production taxes), tend to reduce the incentives for economic activity. They increase the price paid by consumers, which can reduce consumption, and reduce the price received by producers, which can discourage production. The tax collected by the government represents the difference between these two prices, and the net effect is a reduction in the quantity traded on the market.

Tax sharing: Whether the tax is levied on consumers or producers, the impact on the market is similar. The sharing of the tax burden between consumers and producers will depend on the price elasticities of demand and supply. If demand is inelastic to supply, consumers will bear a greater share of the tax burden. Conversely, if supply is inelastic with respect to demand, producers will bear more of the tax burden.

Equilibrium with a tax: Market equilibrium in the presence of a tax is determined by the condition that the price paid by demanders ( $p^{d}$ ) is equal to the price received by suppliers ( $p^{s}$ ) plus the amount of the tax ( $t$ ) :

$p^{d}=p^{s}+t$.

This equation allows us to calculate the new equilibrium prices and quantities traded once the tax is taken into account. The tax creates a distortion in the market by moving the price paid further away from the price received, resulting in a loss of economic efficiency.