Environmental Instrument Choice in a Non-linear World

Abstract

The substantial literature on environmental instrument choice under uncertainty has provided valuable insights using simplifying assumptions of linear marginal cost and benefit curves and additive error terms to determine when and why a price or quantity instrument should be preferred. But empirical analysis has shown that linearity and additivity are not the norm. This paper explores the formal properties of instrument choice when the marginal benefit and marginal cost curves are non-linear; the error term is multiplicative and assumed to be exponential; and the choice is expanded to include comparisons among different price and different quantity regimes, as well as choices between these types. In this more realistic environment, we show that small changes in variance and parameter values can have a significant impact on optimal instrument choices.