Chapter 12: Environmental Protection and Negative Externalities

Q1. What is the difference between a negative externality and a positive externality? Give one example of each.

A: A negative externality imposes costs on third parties (e.g., factory pollution harms neighbors’ health). A positive externality provides benefits to third parties (e.g., a neighbor’s beautiful garden increases your property value). In both cases, the third party is outside the original market transaction.

Q2. In the refrigerator example, why does including the $100/unit external cost of pollution lead to both a higher price and a lower quantity?

A: Including external costs shifts the supply curve to the left (up) by $100. At the original price, quantity supplied falls. The new equilibrium occurs at a higher price ($700 vs. $650) and lower quantity (40,000 vs. 45,000). Consumers pay more, firms produce less, and less pollution is created.

Q3. Why do economists say that pollution is an example of market failure?

A: In an unregulated market, firms consider only their private costs, not the external costs their pollution imposes on society. Since social costs exceed private costs, the market produces more than the socially optimal quantity. The market “fails” because it doesn’t allocate resources efficiently — too much of the polluting good is produced.

Q4. Name the three shortcomings of command-and-control regulation.

A: (1) No incentive to exceed the standard — once firms meet the limit, they stop reducing pollution. (2) Inflexible — same standard and technology for all firms, regardless of their abatement costs. (3) Political loopholes — existing firms lobby for exemptions, resulting in regulations full of fine print and exceptions.

Q5. A firm emits 40 pounds of pollutant per year. The cost of reducing each 10-pound increment is: $200, $600, $1,200, $2,000. If the pollution tax is $800 per 10 pounds, how much will the firm reduce?

A: The firm compares each abatement cost to the $800 tax:

• First 10 lbs: $200 < $800 → Abate
• Second 10 lbs: $600 < $800 → Abate
• Third 10 lbs: $1,200 > $800 → Pay tax
• Fourth 10 lbs: $2,000 > $800 → Pay tax

The firm reduces pollution by 20 pounds and pays the tax on the remaining 20 pounds.

Q6. Why are marketable permits more efficient than command-and-control regulation for achieving the same total pollution reduction?

A: Marketable permits let firms that can reduce pollution cheaply do more of the reduction, while firms with high abatement costs buy permits instead. The total pollution cap is still met, but at a lower overall cost to the economy. Command-and-control forces the same reduction on all firms regardless of cost differences.

Q7. Explain Coase’s railroad-and-farmer example. What is the key insight about property rights?

A: A railroad emits sparks that set a farmer’s field ablaze. If the farmer has the right to an unburned field, the railroad pays for spark-reduction. If the railroad has the right to run freely, the farmer builds a fence. Key insight: As long as property rights are clearly defined, the parties will negotiate the least costly solution — regardless of who holds the rights. The problem arises only when property rights are undefined.

Q8. Why might paying landowners to protect endangered species be more effective than simply banning land use?

A: Banning land use creates a perverse incentive: landowners who discover endangered species on their property face losing the right to use their land. Some may adopt “shoot, shovel, and shut up” strategies. Paying landowners to protect habitat aligns their economic interests with conservation — they gain financially from maintaining suitable environments for endangered species.

Q9. The EPA studied the Clean Air Act from 1970–1990 and found costs of $500 billion and benefits of $22 trillion. Does this mean every environmental regulation passes a cost-benefit test?

A: No. The overall cost-benefit ratio of ~44:1 is favorable, but this is an aggregate measure. When broken down by pollutant type, the benefits of reducing particulates and lead clearly outweigh costs, but for some other pollutants, costs may equal or exceed benefits. Each regulation must be evaluated individually.

Q10. Why is the optimal level of pollution NOT zero?

A: Marginal costs of pollution reduction rise as you eliminate more pollution (cheapest methods first, most expensive last), while marginal benefits of reduction decline (biggest health gains achieved first). At some point, the marginal cost of further reduction exceeds the marginal benefit. Going to zero pollution would mean spending enormous resources for minimal additional benefit — resources better used elsewhere.

Q11. How does the Production Possibility Frontier illustrate the tradeoff between economic output and environmental protection?

A: The PPF shows all efficient combinations of economic output and environmental protection. Moving along the frontier toward more protection requires sacrificing some output (opportunity cost). Points inside the frontier are inefficient — society could have more of both. Low-income countries may choose points with more output; high-income countries may choose more protection. Market-oriented tools help avoid inefficient interior points.

Q12. Why is international cooperation on global warming difficult? What approach may be most practical?

A: High-income countries want all nations to reduce emissions, but low-income countries argue that rich nations historically caused most pollution and that poor nations need economic growth for basic needs. Rich countries may need to help pay for clean technology in poor countries. A centralized global command-and-control system is unlikely, so decentralized, market-oriented approaches (like international cap-and-trade) may be the most practical path forward.