Coasetheorie

Coasetheorie, in English the Coase theorem, is a proposition in law and economics attributed to Ronald Coase. It states that if transaction costs are negligible and property rights are clearly defined, private bargaining will lead to an efficient allocation of resources in the presence of externalities, and the resulting outcome will be independent of who holds the rights initially. In this view, the market can internalize external costs or benefits through voluntary agreements, achieving welfare-maximizing results regardless of the initial allocation of rights.

The theorem relies on two key conditions: zero or very low transaction costs and enforceable property rights. Under these conditions, parties can negotiate compensation to resolve externalities, and the efficient outcome emerges from mutual gains from trade. If the polluter has rights, the affected party can pay for reductions in harm; if the affected party has rights, the polluter can offer compensation to permit continued activity. Either way, efficiency is achieved, though the distribution of surplus may differ with the initial assignment of rights.

In practice, transaction costs are rarely negligible, and information, bargaining power, enforcement, and the number of affected parties often complicate bargaining. Critics note that real-world markets may fail to deliver efficiency and that issues of equity and public welfare may require regulation, taxation, or other governmental interventions. The Coase theorem remains influential in law and economics as a baseline for understanding how property rights and bargaining interact with externalities, while acknowledging real-world frictions.