IBDP Economics 2.1 Demand SL Paper 1 - New Syllabus
Question
(a) Explain two non-price determinants that could decrease the market demand for a good. [10]
(b) Using real-world examples, evaluate the use of indirect taxes to decrease the consumption of demerit goods. [15]
Most-appropriate topic code (CED):
• TOPIC 2.7: Role of government in microeconomics
▶️ Answer/Explanation
(a) Answer:
Market demand refers to the total quantity of a good that all consumers in a market are willing and able to buy at different prices over a given period of time. A non-price determinant of demand is a factor other than the good’s own price that causes the entire demand curve to shift.
1. A decrease in consumer income
For a normal good, a decrease in consumers’ disposable income reduces their purchasing power. As consumers have less income available for spending, they are willing and able to purchase a smaller quantity of the good at every possible price. Therefore, market demand decreases and the demand curve shifts leftward from \(D_1\) to \(D_2\).
For example, during an economic recession, households may experience lower incomes or greater uncertainty about their financial position. They may reduce spending on normal goods such as restaurant meals or holidays. This reduces the market demand for these goods.
2. A change in tastes and preferences
If consumers’ tastes and preferences change against a particular good, fewer consumers will be willing and able to purchase it at each possible price. This causes a decrease in market demand and a leftward shift of the demand curve.
For example, increased awareness of the health risks associated with smoking may cause consumers to develop less favourable preferences towards cigarettes. As a result, fewer consumers may be willing to buy cigarettes at each price, reducing market demand.
A decrease in demand is shown by the entire demand curve shifting from \(D_1\) to \(D_2\), where \(D_2\) lies to the left of \(D_1\). This is different from a movement along the demand curve, which would result from a change in the price of the good itself.
Therefore, both a decrease in income for a normal good and an unfavourable change in consumer preferences can reduce market demand without any change in the price of the good itself.
(b) Answer:
A demerit good is a good that is considered harmful to consumers and is likely to be overconsumed when consumers do not fully recognize the negative consequences of consumption. Consumption may also impose costs on third parties, creating negative consumption externalities.
Because consumers may ignore some of these external costs, the free market may result in a quantity consumed that is greater than the socially optimal quantity. Governments can use an indirect tax to increase the price of the demerit good and discourage its consumption.
Effect of the tax: An indirect tax increases the cost of supplying the good, causing the supply curve to shift upwards/leftwards. The equilibrium price paid by consumers increases, while the quantity bought and sold decreases. Therefore, consumption of the demerit good falls.
In an externality diagram, the market quantity is above the socially optimal quantity because consumers consider their private benefits and costs rather than the full external cost. A corrective tax can increase the private cost of consumption and move the market outcome closer to the socially optimal level.
For example, governments impose taxes on cigarettes and other tobacco products. The higher price gives consumers a financial incentive to reduce cigarette consumption. This can reduce smoking-related health problems and potentially reduce external costs placed on healthcare systems and other members of society.
One important advantage is that the effectiveness of the tax depends on price elasticity of demand (PED). If demand is relatively price elastic, an increase in price causes a proportionately larger decrease in quantity demanded. An indirect tax would therefore be relatively effective in reducing consumption.
However, if demand is price inelastic, consumers respond relatively little to the increase in price. This can occur with addictive demerit goods such as cigarettes, where consumers may continue buying the product despite higher prices. In this situation, the tax may raise substantial government revenue but have a relatively small effect on consumption.
Therefore, the success of the policy in reducing consumption depends not simply on the size of the tax but also on the responsiveness of consumers to the resulting price increase.
There are also equity considerations. Indirect taxes can be regressive because lower-income households may spend a greater proportion of their income on the taxed good. If these consumers continue purchasing the demerit good despite the higher price, the tax places a relatively large financial burden on them. Thus, a policy that improves allocative efficiency may simultaneously create an equity problem.
However, if taxation successfully reduces consumption among lower-income households, it may also produce significant long-term health benefits for these households. The overall equity effect therefore depends on how consumers respond to the tax and how the government uses the tax revenue.
The government may also face difficulties in setting the appropriate tax. Ideally, the tax should reflect the external cost created by consumption. However, accurately measuring the external cost of smoking, alcohol consumption or other demerit goods can be difficult. If the tax is too low, consumption may remain above the socially optimal level. If it is too high, consumption could be reduced below the socially optimal level, creating another form of inefficiency.
Another limitation is the possibility of illegal markets and tax avoidance. If taxes make cigarettes or other demerit goods significantly more expensive, some consumers may purchase untaxed or illegally traded alternatives. This reduces the effectiveness of the tax in reducing consumption through the legal market and may also reduce government tax revenue.
Indirect taxes may also contribute to inflation. Because the tax raises the prices of the affected goods, it directly increases their price level. If the taxed goods form an important part of household expenditure or are inputs into other goods and services, the tax may contribute to broader inflationary pressure.
Nevertheless, indirect taxation can provide the government with substantial tax revenue. This revenue could be used to finance healthcare, education or information campaigns designed to further reduce consumption. For example, revenue from tobacco taxation could help fund healthcare services associated with smoking-related illnesses.
Real-world evaluation: Tobacco taxation illustrates both the strengths and limitations of the policy. Higher cigarette taxes can increase the financial cost of smoking and encourage some consumers to quit or reduce consumption. However, because nicotine is addictive, demand among existing smokers may be relatively inelastic, meaning that higher taxes do not necessarily produce an equally large reduction in consumption.
Similarly, taxes on alcohol and sugary drinks can increase prices and provide an incentive to reduce consumption. Their effectiveness depends on factors such as PED, the availability of substitutes and the extent to which consumers are aware of the health costs associated with consumption.
Overall evaluation: Indirect taxes are an effective market-based method of reducing consumption when demand is sufficiently price elastic and when the tax is appropriately related to the external costs generated by the demerit good. They can improve resource allocation by reducing overconsumption and can also generate government revenue.
However, indirect taxes are less effective when demand is highly price inelastic, particularly for addictive goods. They may also be regressive, encourage illegal markets and create inflationary pressure. Furthermore, governments cannot easily determine the precise monetary value of the externality.
Therefore, indirect taxes are desirable but should not normally be used as the only policy. Their effectiveness is greatest when combined with policies such as information campaigns, restrictions on advertising and regulations on consumption. The final judgement depends particularly on the PED of the good, the size of the externality, the availability of substitutes and the government’s ability to design and enforce the tax effectively.
Question
(a) Explain how a decrease in the price of travelling by train might affect the price and output of its substitutes and of its complements. [10]
(b) Using real-world examples, evaluate the view that the government should never provide subsidies to firms. [15]
Most-appropriate topic code (CED):
• TOPIC 2.7: Role of government in microeconomics – part (b)
▶️ Answer/Explanation
(a) Answer:
A substitute is a good or service that can be used instead of another good or service, while a complement is a good or service that is consumed together with another good or service.
If the price of travelling by train decreases, assuming other factors remain constant (ceteris paribus), rail travel becomes relatively cheaper compared with alternative forms of transport. This causes an increase in the quantity demanded of train travel.
As consumers switch from alternative forms of transport to trains, the demand for substitutes for train travel is likely to decrease. For example, road travel may be a substitute for travelling by train.
The decrease in demand for road travel causes the demand curve for road transport to shift leftward. At the original price, there is excess supply, creating downward pressure on the price.
The new market equilibrium therefore results in a lower price and lower output of the substitute. Thus, a decrease in the price of train travel is likely to reduce both the price and quantity of its substitutes.
In contrast, a complement is a good or service used together with train travel. Examples could include food and drinks purchased at railway stations.
Because train travel has become cheaper, consumers are likely to undertake more rail journeys. This increases the demand for complementary goods and services associated with those journeys.
The increase in demand for the complement shifts its demand curve rightward. At the original price, there is excess demand, creating upward pressure on price.
The new equilibrium therefore results in a higher price and higher output of the complementary good.
A demand and supply diagram for a substitute can show demand shifting left, causing equilibrium price and output to fall. A second demand and supply diagram for a complement can show demand shifting right, causing equilibrium price and output to rise.
Therefore, a decrease in the price of train travel is likely to have opposite effects on its substitutes and complements: the price and output of substitutes are likely to fall, while the price and output of complements are likely to rise.
(b) Answer:
A subsidy is a payment made by the government to a firm or producer that reduces the effective cost of production. Subsidies can therefore lower firms’ costs and encourage an increase in production.
The view that governments should never provide subsidies is based on the possibility that subsidies distort market signals, create inefficiency and impose costs on taxpayers.
When a government provides a subsidy to firms, their costs of production fall. This increases the quantity that firms are willing and able to supply at each price, causing the supply curve to shift to the right.
The market equilibrium price paid by consumers may fall, while the quantity of the good or service produced and consumed increases.
A demand and supply diagram can show the supply curve shifting right following the introduction of a subsidy, with the consumer price falling and equilibrium quantity increasing.
One disadvantage is resource misallocation. A subsidy may encourage firms to produce more of a good than would otherwise be justified by market signals. Resources such as labour and capital may therefore be diverted from other potentially more valuable uses.
Subsidies also involve an opportunity cost. Government expenditure on subsidies cannot be used for alternative purposes such as education, healthcare, infrastructure or debt reduction.
If subsidies are financed through higher taxation or government borrowing, there may also be wider economic costs. The opportunity cost becomes particularly important when government finances are already under pressure.
Subsidies can also reduce productive efficiency. Firms receiving financial support may have less incentive to reduce their costs, innovate or improve productivity because part of their costs is effectively covered by the government.
This can create government failure if governments continue supporting inefficient firms simply because they are politically influential or provide employment.
Subsidies can also affect foreign producers. If a government subsidizes domestic firms, those firms may be able to sell goods at lower prices in international markets. This can disadvantage foreign producers and potentially distort international trade.
However, the claim that governments should never provide subsidies is too absolute. Subsidies can correct certain market failures and achieve wider economic and social objectives.
One important justification is the presence of a positive externality. If consumption or production creates external benefits that are not reflected in the market price, the free market may produce less than the socially optimal quantity.
A government subsidy can reduce the effective price and increase consumption or production toward the socially optimal level.
For example, subsidies for education can encourage greater consumption of education. Education generates benefits to individuals through higher skills and earnings, but it can also generate wider benefits through higher productivity and greater tax revenues.
Subsidies can similarly support renewable energy. Governments may subsidize solar or wind power because reducing fossil-fuel use can generate environmental benefits that are not fully reflected in market prices.
In such circumstances, the subsidy can help internalize the positive externality and encourage a level of output closer to the socially desirable level.
Subsidies can also increase the income and revenue of particular producers. This may be important in industries considered strategically or socially significant, such as agriculture, energy or public transport.
For example, agricultural subsidies may help farmers cope with volatile prices and incomes. Agriculture can also have wider benefits associated with food security and rural employment.
Subsidies may also help low-income consumers. If the government subsidizes essential goods or services, the resulting reduction in prices can improve affordability and increase the real incomes of poorer households.
Another justification is the protection of key or strategic industries. Governments may provide temporary financial support to industries considered important for national security, employment or long-term economic resilience.
Subsidies can also be used to help domestic producers compete with imports. This may protect domestic employment and give firms time to improve productivity and become more competitive.
However, protection through subsidies can become problematic if support continues indefinitely. Firms may become dependent on government assistance rather than improving their international competitiveness.
The effectiveness of a subsidy therefore depends partly on its objective, size and duration. A temporary subsidy designed to correct a clearly identified market failure may be justified, while a permanent subsidy to an inefficient firm may generate substantial opportunity costs and resource misallocation.
A real-world example is the use of renewable-energy subsidies by governments to encourage investment in clean technologies. Financial support can reduce the cost of renewable energy and encourage firms and consumers to move away from fossil fuels, generating environmental benefits.
However, poorly designed energy subsidies can be expensive for governments and may support technologies that would not otherwise be competitive. This illustrates why the design of the policy matters.
Another example is agricultural subsidies. These can stabilize farm incomes and support domestic food production, but they may also encourage overproduction, create government expenditure and distort international markets.
The key issue is therefore whether the benefits created by the subsidy exceed the costs associated with government expenditure and market distortion.
Overall evaluation: The government should not provide subsidies automatically to every industry because subsidies can create resource misallocation, reduce productive efficiency, impose opportunity costs and distort international competition.
Nevertheless, it would be incorrect to conclude that subsidies should never be provided. Where there are positive externalities, equity concerns, strategic industries or other clearly identified market failures, a well-designed subsidy can increase social welfare.
The strongest judgement is that subsidies are most justified when they address a specific market failure or clearly defined social objective, and when the expected benefits exceed the opportunity cost of government spending.
Therefore, subsidies should be assessed on a case-by-case basis. Temporary and targeted subsidies are more likely to be justified than permanent support for inefficient firms. The claim that the government should never provide subsidies is consequently not supported.