Chapter 4.3 – Price Ceilings and Price Floors

Definitions and Key Concepts

Price controls are government-imposed limits on the prices that can be charged for goods and services. They are used to address perceived unfairness or market failures but often have unintended consequences.

• Price ceiling: Legally determined maximum price for a good or service. Examples include rent control and price gouging laws.

• Price floor: Legally determined minimum price for a good or service. Examples include minimum wage and agricultural price supports.

• Binding price control: A control that prevents the market from reaching equilibrium. A ceiling is binding if set below equilibrium price; a floor is binding if set above equilibrium price.

• Shortage: Occurs when quantity demanded exceeds quantity supplied at the controlled price. Created by a binding price ceiling.

• Surplus: Occurs when quantity supplied exceeds quantity demanded at the controlled price. Created by a binding price floor; in labor markets, this results in unemployment.

• Illegal (black) market: Transactions at prices violating the regulation, such as renting apartments above the legal rent under rent control.

• Deadweight loss: Reduction in economic surplus due to fewer units being traded than at equilibrium.

Key Ideas

• Binding price controls limit the quantity traded to the smaller of quantity demanded or supplied (the "short side" of the market).

• Binding price ceilings (e.g., rent control) cause shortages, transfer producer surplus to renters, and lead to non-price rationing (waiting lists, discrimination, illegal payments).

• Binding price floors (e.g., minimum wage) cause surpluses, transfer consumer surplus to workers, and result in unemployment.

• Transfers between buyers and sellers are not a loss to society, but the reduction in traded units is—the deadweight loss.

• Economic efficiency is reduced by price controls; this is a positive (descriptive) statement, while desirability is a normative (prescriptive) question.

• Minimum wage debates focus on income gains versus job losses; empirical studies (e.g., Card and Krueger) show mixed effects.

• Price gouging laws prevent windfall gains but create shortages and discourage supply increases after disasters.

Examples

• Rent control in New York City creates shortages and black markets.

• Minimum wage laws may increase incomes for some workers but reduce employment for others.

Additional info: Price controls are often implemented for equity reasons but can lead to inefficiency and unintended consequences.

Chapter 4.4 – The Economic Effect of Taxes

Definitions and Key Concepts

Taxes affect market outcomes by changing prices and quantities traded, and their burden is shared between buyers and sellers depending on market sensitivities.

• Per-unit (excise) tax: Fixed dollar amount tax on each unit sold (e.g., gasoline, cigarettes).

• Tax incidence: Division of the tax burden between buyers and sellers.

• Buyers’ burden: Increase in price paid by buyers due to the tax.

• Sellers’ burden: Decrease in price received by sellers after paying the tax.

• Tax revenue: Total amount collected by the government ().

• Excess burden (deadweight loss): Loss of consumer and producer surplus not offset by tax revenue.

• Efficient tax: Tax with a small excess burden relative to the revenue raised.

Key Ideas

• A tax on sellers shifts the supply curve up by the tax amount; a tax on buyers shifts the demand curve down.

• After a tax, quantity sold falls, buyers pay more, sellers receive less. The price gap equals the tax.

• Some surplus becomes government revenue; some disappears as excess burden.

• Incidence depends on the relative price sensitivity (elasticity) of demand and supply, not on who legally pays the tax.

• The less sensitive side (steeper curve) bears more of the tax burden.

• Example: FICA tax is legally split, but workers bear most due to inelastic labor supply.

Example

• Gasoline tax: If demand is inelastic, consumers bear most of the tax.

Additional info: Tax incidence analysis is crucial for understanding policy impacts on different groups.

Chapter 4 Appendix – Quantitative Demand and Supply Analysis

Definitions and Key Concepts

Demand and supply equations allow precise calculation of equilibrium and analysis of market interventions.

• Demand equation: ; quantity demanded decreases as price increases.

• Supply equation: ; quantity supplied increases as price increases.

• Equilibrium condition: ; solve for equilibrium price and quantity.

• Price intercept: Price at which quantity is zero; highest price buyers will pay (demand), lowest price sellers will accept (supply).

• Consumer surplus: Area below demand curve and above market price.

• Producer surplus: Area above supply curve and below market price.

• Economic surplus: Sum of consumer and producer surplus; maximized at competitive equilibrium.

Key Ideas

• Equations provide exact solutions for equilibrium and surplus calculations.

• Price controls: Check if binding by comparing controlled price to equilibrium price.

• Deadweight loss is the surplus lost due to reduced quantity traded.

Example

• Given and , set to solve for equilibrium price and quantity.

Additional info: Graphical and algebraic methods complement each other in market analysis.

Chapter 5.1 – Externalities and Economic Efficiency

Definitions and Key Concepts

Externalities occur when market transactions affect third parties, leading to inefficiency and market failure.

• Externality: Benefit or cost affecting someone not directly involved in the transaction.

• Negative externality: Cost imposed on others (e.g., pollution).

• Positive externality: Benefit received by others (e.g., education).

• Private cost/benefit: Cost/benefit to producer/consumer.

• Social cost/benefit: Total cost/benefit including external effects.

• Marginal private/social cost/benefit: Additional cost/benefit from one more unit.

• Economic efficiency: Achieved when marginal social benefit equals marginal social cost.

• Market failure: Market does not produce the efficient output; externalities are a cause.

• Property rights: Rights to exclusive use of property; incomplete rights lead to externalities.

Key Ideas

• Negative externality: Market supply reflects only marginal private cost; social cost is higher, leading to overproduction.

• Positive externality: Market demand reflects only marginal private benefit; social benefit is higher, leading to underproduction.

• Deadweight loss arises from the gap between private and social curves.

• Externalities result from incomplete property rights.

Example

• Pollution from electricity generation imposes health costs not reflected in market price.

Additional info: Efficient quantity is where .

Chapter 5.2 – Private Solutions to Externalities: The Coase Theorem

Definitions and Key Concepts

The Coase theorem suggests that private bargaining can solve externality problems if property rights are well-defined and transaction costs are low.

• Coase theorem: Efficient outcome through bargaining regardless of property right assignment, if transaction costs are low.

• Transactions costs: Costs incurred in negotiating and enforcing agreements.

• Internalizing an externality: Making the party creating the externality bear its full cost or benefit.

• Efficient pollution reduction: Achieved when marginal benefit equals marginal cost.

Key Ideas

• Efficient pollution reduction is not zero; balance benefits and costs.

• Assignment of property rights affects who pays, not the outcome.

• Coase theorem requires enforceable rights, low transaction costs, and knowledge of costs/benefits.

• Private solutions fail when many parties are involved or transaction costs are high.

Example

• Neighbors negotiate over noise from a factory; outcome is efficient if bargaining is feasible.

Additional info: Government often helps define and enforce property rights.

Chapter 5.3 – Government Policies to Deal with Externalities

Definitions and Key Concepts

Government can address externalities through taxes, subsidies, regulation, and market-based approaches.

• Pigovian tax: Tax equal to marginal external cost; corrects negative externalities.

• Pigovian subsidy: Subsidy equal to marginal external benefit; corrects positive externalities.

• Command-and-control: Direct regulation of pollution or required technology.

• Market-based approach: Uses prices and incentives (taxes, tradable allowances).

• Tradable emissions allowances (cap-and-trade): Government sets cap, firms trade allowances.

Key Ideas

• Pigovian tax shifts supply to reflect social cost, reducing quantity to efficient level and eliminating deadweight loss.

• Pigovian subsidy shifts demand to reflect social benefit, increasing quantity to efficient level.

• Command-and-control is inefficient if firms have different abatement costs.

• Cap-and-trade achieves reduction at lowest cost; firms trade allowances based on abatement costs.

Example

• Carbon tax internalizes climate change externality; cap-and-trade for sulfur dioxide reduced compliance costs.

Additional info: Market-based policies are generally preferred for efficiency.

Chapter 5.4 – Four Categories of Goods

Definitions and Key Concepts

Goods are classified by rivalry and excludability, affecting how markets supply them and the potential for market failure.

• Rivalry: One person's consumption prevents others from consuming the same unit.

• Excludability: Non-payers can be prevented from consuming the good.

• Private good: Rival and excludable (e.g., hamburger).

• Public good: Nonrival and nonexcludable (e.g., national defense).

• Quasi-public good: Excludable but nonrival (e.g., cable TV).

• Common resource: Rival but nonexcludable (e.g., fish in the ocean).

• Free riding: Benefiting without paying; leads to undersupply of public goods.

• Tragedy of the commons: Overuse of common resources due to ignored external costs.

Categories Table

Key Ideas

• Private good demand: horizontal sum of individual demand curves.

• Public good demand: vertical sum of individual willingness to pay.

• Free riding prevents efficient supply of public goods; governments use cost–benefit analysis.

• Common resources are overused due to lack of exclusion; solutions include community norms, taxes, quotas, or permits.

Example

• National defense is a public good; fish stocks are a common resource subject to overfishing.

Additional info: Classification helps determine appropriate policy interventions.