Prices Versus Quantities: Technology Choice,Uncertainty and Welfare

Technological improvements have proven essential in mitigating environmental problems such as climate change, depletion of the ozone layer and acid rain. While it is well-known that price- and quantity-based regulatory instruments provide different investment levels, the effects on the choice between different technologies have received scant attention. This paper expands on the prices versus quantities literature by investigating firms’ technology choice in the face of demand and supply side uncertainty. I show that the regulator can not design tradable emissions permits and an emissions tax such that the two regimes are equivalent, even in terms of expected values. Moreover, a tax encourages the most flexible abatement technology if and only if stochastic costs and the equilibrium permit price have sufficiently strong positive covariance, compared with the variance in consumer demand for the good produced. Finally, the firms’ technology choices are socially optimal under tradable emissions permits, but not under an emissions tax.