Efficient Dynamic Pollution Taxation in an Uncertain Environment

This paper analyzes efficient pollution taxation within a stochastic model of endogenous growth. Pollution is a by-product of production and causes disutility. Furthermore, the productivity which results from environmental quality is uncertain. This reflects e.g. uncertain capital depreciation induced by natural disasters like hurricanes or floods. This uncertainty is shown to raise an ambiguous impact on the optimal pollution level as well as on optimal environmental taxation. Market equilibrium turns out to be suboptimal, since the households mis-perceive their individual impact on pollution. Conditions for welfare maximizing pollution taxation are stated and it is shown that a direct pollution tax is not appropriate to yield Pareto-optimal growth. Instead, a linear capital income tax together with a linear abatement subsidy build an efficient tax scheme, if secondarily the governmental budget is balanced. Moreover, an increase in the riskiness of environmental productivity may even lead to an increase in the optimal pollution level and to a decrease in optimal environmental taxation, depending predominantly on the preference parameters.