3. El Teorema de Coase
I. Externalities and Social Costs
Externalities occur when the costs or benefits of an action affect third parties who do not participate directly in the transaction.
The goal of analyzing these issues is to maximize social surplus, which includes consumer surplus, producer surplus, plus everyone else’s surplus (bystanders).
A. Types and Definitions
Private cost: A cost paid by the consumer or producer in the market.
External cost (Negative externality): A cost assumed by a party outside the exchange.
The social cost is the sum of the private cost and the external cost.
External benefit (Positive externality): A benefit received by a party outside the exchange.
B. Examples
External Costs:
The market price of a good does not reflect its complete social cost.
Antibiotic use leads to increased bacterial resistance. Since users ignore external costs, antibiotics are overused (QMarket > QEfficient).
Pollution (e.g., factory smoke or contamination of a river).
Traffic congestion (where driving without a toll imposes costs on others).
External Benefits:
Vaccinations reduce the spread of disease, benefiting others in the community.
Bee pollination resulting from honey production.
When external benefits are ignored, the market leads to underproduction (QMarket < QEfficient).
II. The Coase Theorem: Principles and Conditions
A. Core Theorem Statement
The Coase theorem states that if transaction costs are low and property rights are clearly defined, private negotiations will ensure that the market equilibrium is efficient, even in the presence of externalities.
Under these ideal conditions (costless transactions), the ultimate result (which maximizes the value of production) is independent of the initial legal assignment of rights.
This idea—that resources go where they are most valuable—was already present since Adam Smith.
B. Transaction Costs and Reciprocity
Transaction costs are all costs needed to reach and enforce an agreement, including: negotiating, measuring, drawing up contracts, and ensuring compliance.
In the real world, these costs are often significant.
The true contribution of Coase is emphasizing that when transaction costs are high, the initial allocation of property rights does matter for efficiency.
In this scenario, society often has to settle for the second best option.
Reciprocal Nature of Externalities: The problem is not merely restraining one party (A) from harming another (B).
Eliminating harm to B imposes harm on A; the core question is who should be allowed to harm whom.
The problem is about avoiding the more serious harm and balancing benefits and costs for both sides.
C. Property Rights and Negotiation
A property right is conceptualized as the right to perform certain physical actions, not just owning a physical entity (like land).
Negotiations require adequately defined property rights to be effective.
The party who initiates the negotiation often influences the final price, potentially moving it closer to the price asked (price pedido or as price).
III. Solutions to Externalities and Conflict Resolution
A. Private Solutions and Internalization
Internalizing an externality means adjusting incentives so that decision-makers take all social costs and benefits into account.
Negotiation is the everyday procedure for minimizing negative externalities, often termed "work it out for yourselves".
If transaction costs are low, the market works, as seen in the case of bee pollination where farmers pay beekeepers, thus internalizing the benefit.
For high transaction costs, Coase’s framework suggests alternatives to individual private property to minimize costs, such as:
Firms: Substituting administrative decisions for market transactions among cooperating factors.
Communal property systems (e.g., Elinor Ostrom's work), which minimize transaction costs for shared resources.
Intermediaries and Arbitrage: Professionals could emerge to reduce transaction costs and mitigate outcomes based on unequal negotiation skills.
Negotiation vs. Prohibition: For actions deemed "crimes without victims" (like drug use or prostitution), Coase's approach suggests negotiation (e.g., paying a person to stop the activity) is preferable to government prohibition (a 100% Pigouvian tax).
B. Traditional Government Solutions (The Pigovian Tradition)
Economists traditionally followed Pigou, analyzing the divergence between private and social products.
1. Pigouvian Taxes and Subsidies
A Pigouvian tax (on external costs) or subsidy (on external benefits) is designed to adjust the market price to reflect the social cost or social value.
A tax on a good with an external cost reduces deadweight loss and raises revenue, unlike a tax on an ordinary good.
Problems: These solutions face significant issues concerning information and incentives.
Governments lack the perfect information required to set the optimal tax rate needed to achieve the efficient quantity.
Taxes can be distorted by political pressure (lobbies) rather than maximizing efficiency.
A tax on the producer alone may lead to unduly high costs for prevention if it doesn't incentivize those harmed to also make adjustments.
2. Command and Control (C&C)
This involves direct regulation, prohibition, or setting quantity restrictions (like zoning regulations).
Problems: C&C is often inefficient because the government lacks the local knowledge to choose the least costly method for reduction across different firms or individuals, thereby increasing costs.
C&C is generally preferred only when the best approach is universally known and high compliance is necessary (e.g., smallpox eradication).
C. Market-Based Government Solutions
Tradable Permits/Allowances: These systems define the right to pollute (e.g., 1 ton of SO2 emission) and allow firms to buy and sell these rights.
This is a successful application of the Coase theorem, as it clarifies rights and minimizes transaction costs through market mechanisms.
Trading ensures pollution reduction occurs at the lowest overall cost, as firms with lower abatement costs will sell permits to firms with higher costs.
This mechanism creates incentives by effectively taxing dirty energy and subsidizing clean energy.
Comparison to Pigouvian Taxes:
If the exact efficient quantity must be guaranteed (e.g., to stay below an environmental threshold), tradable allowances are superior because the quantity is fixed.
If the cost of damage is known but supply/demand are changing, Pigouvian taxes are better because they adjust automatically.
If assuming perfect information (i.e., the government knows the optimal tax and quantity), both taxes and allowances yield the same efficient equilibrium and the same government revenue.
D. The Role of Courts (Adjudication)
When transaction costs are high, Coase suggested courts/tribunals as a solution.
Adjudication is a process for deciding who has which rights, aiming to maintain the continuity of expectations and resolve conflicting claims based on established principles.
The courts often consider the economic consequences of their decisions, weighing utility against harm when determining nuisance.
Critique: Coase fell into the same error he criticized by assuming judges possess the knowledge required to weigh social benefits and costs accurately.