Pigouvian Taxation
Taxing activities to internalize the social cost of externalities.
Pigouvian taxation, named for Arthur Cecil Pigou's 1920 The Economics of Welfare, prescribes taxing activities that produce negative externalities at a rate equal to the marginal external cost they impose, thereby aligning private incentives with social costs and restoring allocative efficiency. The corresponding instrument for positive externalities is a Pigouvian subsidy. The framework is the orthodox economic prescription for problems including pollution, congestion, tobacco and alcohol consumption, and carbon emissions, and it sits in productive tension with the Coasean alternative of well-defined property rights and private bargaining. In practice, marketable permit systems are often preferred to direct Pigouvian taxes for political-economy reasons (visibility, distributional concerns, calibration uncertainty), though the underlying analytical logic is closely related.
Core components
- Marginal external cost
- Tax equal to externality
- Pigouvian subsidies for positive externalities
- Internalization principle
- Equivalence to permit-quantity instruments under certainty
- Double-dividend possibility (revenue use)
Primary use case
Environmental policy (carbon taxes, emissions fees); tobacco, alcohol, and sugar taxation on health-externality grounds; congestion pricing; analysis of optimal tax design under externalities; framework for welfare analysis of corrective taxes.
Common criticisms
- Marginal external cost is difficult to measure precisely, leading to calibration uncertainty
- political economy of corrective taxes often produces regressive distributional consequences absent rebate or transfer mechanisms
- Coase critique that private bargaining could resolve externalities under low transaction costs
- permit-trading systems often preferred politically
- Weitzman (1974) critique on prices vs quantities under marginal-cost uncertainty.
Lineage
- Siblings
- Coase Theorem, Tragedy of the Commons