The Effect of Uncertainty on Pollution Control Policy

I study a class of differential games of pollution control with profit functions that are polynomial in the global pollution stock. Given an emissions path satisfying mild regularity conditions, a simple polynomial ambient transfer scheme is exhibited that induces it in Markov-perfect equilibrium (MPE). Proposed transfers are a polynomial function of the difference between actual and desired pollution levels; moreover, they are designed so that in MPE no tax or subsidy is ever levied. Their applicability under stochastic pollution dynamics is studied for a symmetric game of polluting oligopolists with linear demand. I discuss a quadratic scheme that induces agents to adopt Markovian emissions strategies that are stationary and linear-decreasing in total pollution. Total expected ambient transfers are always non-positive and increase linearly in volatility and the absolute value of the slope of the inverse demand function. However, if the regulator is interested in inducing a constant emissions strategy then, in expectation, transfers vanish.