IBDP Economics 2.8 Market failure—externalities and common pool or common access resources HL Paper 1 - New Syllabus

(a) Answer:

An externality occurs when the production or consumption decision of one economic agent creates costs or benefits for third parties that are not reflected in the market price. A production externality therefore arises when the production of a good affects third parties who are not directly involved in the production decision.

Firms normally make production decisions based on their private costs and private benefits. The firm’s objective is to choose an output level that maximizes its own profit. Therefore, it considers the costs it directly faces, such as wages, raw materials, energy and machinery, but does not automatically consider costs imposed on third parties.

For a negative production externality, the social cost of production is greater than the firm’s private cost. This can be expressed as:

Social cost = Private cost + External cost

For example, a factory may release pollution into a river while producing goods. The factory pays for its workers, raw materials and machinery, so these costs are included in its private costs. However, local residents may suffer from polluted water and environmental damage. These costs are imposed on third parties and are therefore external costs.

Because the firm does not directly pay for the pollution, it has little private incentive to include this external cost when deciding its level of production. Consequently, the firm’s marginal private cost (MPC) is lower than the marginal social cost (MSC).

The firm will choose its profit-maximizing output where its own marginal benefit or marginal revenue is equal to its marginal private cost. However, the socially optimal output occurs where marginal social benefit (MSB) = marginal social cost (MSC).

Since MSC > MPC for a negative production externality, the firm’s private profit-maximizing output is greater than the socially optimal output. The market therefore overproduces the good and creates a market failure.

The reason the firm does not take the externality into account is therefore that the external cost is not included in the firm’s private costs. Unless government regulation, taxation, tradable permits or another mechanism causes the firm to internalize the external cost, the firm has little economic incentive to reduce the externality.

A negative production externality diagram should show MSC above MPC, with the firm’s market equilibrium output greater than the socially optimal output. The diagram should identify the resulting welfare loss and the overproduction caused by the externality.

Therefore, firms do not normally take externalities into account because their production decisions are based on the costs and benefits that they directly face. Unless the external effect is internalized, third-party costs or benefits remain outside the firm’s private decision-making.

(b) Answer:

Tradable permits are a government policy used to control negative externalities such as carbon emissions. Under a tradable permit or cap-and-trade system, the government sets a maximum level of total emissions and issues permits that allow firms to emit a specified quantity of carbon dioxide. Firms can buy and sell these permits in a market.

The government can gradually reduce the total number of permits available. This lowers the overall emissions cap and aims to reduce carbon emissions over time, helping to achieve sustainability.

One major advantage of tradable permits is that they provide certainty over the maximum quantity of emissions. If the government sets an appropriate emissions cap, total emissions cannot exceed the number of permits issued, assuming effective monitoring and enforcement.

Tradable permits can also encourage firms to reduce emissions at the lowest possible cost. Firms that can reduce emissions relatively cheaply have an incentive to do so and sell their unused permits. Firms for which reducing emissions is more expensive can purchase permits instead.

This creates an economic incentive for firms to invest in cleaner production methods. Over time, a sufficiently tight and declining cap can encourage technological innovation and reduce dependence on carbon-intensive production.

The European Union Emissions Trading System (EU ETS) is an important real-world example. The EU ETS uses a cap-and-trade system covering major sources of greenhouse-gas emissions. The overall quantity of allowances is limited and the cap is reduced over time, creating an incentive for covered firms to reduce emissions.

However, the effectiveness of tradable permits depends heavily on the government’s ability to set an appropriate emissions cap. If too many permits are issued, the price of permits may be low and firms may have little incentive to invest in cleaner technology. The policy may then fail to produce sufficiently large reductions in carbon emissions.

There are also difficulties in measuring and monitoring emissions. Governments must be able to accurately measure firms’ emissions and enforce compliance. If monitoring is weak, firms may exceed their permitted emissions without facing the intended consequences.

Another disadvantage is that the price of permits can fluctuate. Uncertainty about future permit prices may make it more difficult for firms to plan long-term investment in low-carbon technology. If permit prices become very low, the incentive to reduce emissions may weaken.

Tradable permits may also create distributional effects. Firms facing high costs of reducing emissions may purchase permits and pass some of these costs on to consumers through higher prices. Workers and consumers in carbon-intensive industries may therefore be negatively affected by a strict emissions cap.

Carbon taxes provide an alternative approach. A government can impose a tax on each unit of carbon emissions. This increases the private cost of polluting and encourages firms to reduce emissions because pollution becomes more expensive.

A carbon tax can provide firms with a relatively clear price incentive to reduce emissions. Unlike a permit system, however, the government does not directly know the final quantity of emissions that will result from a particular tax rate. The effectiveness therefore depends on how responsive firms are to the tax.

Governments can also use subsidies for clean technologies. Subsidizing renewable energy, energy efficiency or low-carbon technology reduces the cost of adopting cleaner production methods. This can encourage innovation and reduce emissions without relying entirely on firms purchasing permits.

For example, subsidies for renewable electricity can encourage investment in solar and wind power, reducing dependence on fossil fuels. However, subsidies can impose a significant cost on government budgets and may be less effective if they do not sufficiently change firms’ incentives.

The effectiveness of tradable permits therefore depends on the specific circumstances. If emissions can be measured accurately, monitoring is effective and the government establishes a sufficiently strict declining cap, tradable permits can achieve substantial reductions while allowing firms flexibility over how they reduce emissions.

However, where emissions are difficult to monitor or governments lack reliable information about the appropriate emissions cap, a carbon tax or a combination of policies may be more effective. A carbon tax can provide a direct and predictable financial incentive to reduce pollution, while subsidies can accelerate the development of cleaner technologies.

The EU ETS demonstrates both the potential and the limitations of tradable permits. Its effectiveness depends on the overall design of the scheme, including the emissions cap, allocation of allowances, monitoring and enforcement. A poorly designed permit market may result in low permit prices and weak incentives, whereas a sufficiently restrictive cap can provide a stronger incentive for emissions reductions.

Overall evaluation: Tradable permits can be a highly effective method of reducing carbon emissions because they establish a direct limit on total emissions while allowing firms to choose the least-cost method of adjustment. However, it is too strong to conclude that they are always the best policy.

The best policy depends on the government’s ability to measure emissions, enforce the system and establish an appropriate cap, as well as the characteristics of the industries involved. A combination of tradable permits, carbon taxes and subsidies for clean technology may be more effective than relying on tradable permits alone.

Therefore, tradable permits are potentially one of the most effective instruments for achieving sustainability because they directly control the quantity of emissions. Nevertheless, their success is conditional on effective monitoring, enforcement and a sufficiently ambitious emissions cap. In many circumstances, combining them with other policies is likely to provide a more effective long-term response to the threat posed by carbon emissions.