Pigouvianos

Pigouvianos are adherents of the economic approach associated with Arthur C. Pigou, focusing on externalities and welfare economics. They argue that markets often fail to reflect costs or benefits imposed on third parties, leading to inefficient outcomes. The central policy prescription is to internalize externalities through price adjustments that align private incentives with social costs. The standard tool is the Pigovian tax: a tax levied on a good or activity equal to the marginal external cost it imposes at the socially optimal level of output. When external benefits exist, Pigouvianos support subsidies or public provision to raise private incentives toward the social optimum. In practice, policy instruments include pollution taxes, carbon pricing, congestion charges, and other levies, as well as regulations when price mechanisms are infeasible. While taxes are central, some supporters emphasize a mix of taxes, subsidies, and regulatory measures rather than a single instrument.

Historically, the concept stems from Arthur Pigou's The Economics of Welfare (1920) and has influenced environmental policy and public finance in many countries. The approach is often contrasted with market-based or transaction-cost theories such as the Coase theorem, which argue that bargaining can internalize externalities without government intervention under certain conditions.

Critics point to challenges in estimating external costs, potential equity effects, administrative costs, and the risk of incorrect tax levels. Proponents note that even imperfect Pigovian policies can improve welfare relative to laissez-faire, especially when externalities are clearly identified and measurable.