Dynamics of pollution control when damage is sensitive to the rate of pollution accumulation

Abstract

Economic models which take into account the long-term effects of pollution in the environment specify pollution damage as a function of the accumulated stock. Several economists have proposed another formulation where damage is a function of the time derivative of the pollution stock. This paper considers the intertemporal efficiency implications of this formulation. The first specification is qualitative and the objective functional includes both the rate of change and the level of the pollution stock. The second specification is a stylized climate change model with a linear damage function where damage depends only on the rate of increase in global temperature. The analysis reveals that the efficiency properties of optimal pollution control are very sensitive to this change in the damage function. Intertemporal efficiency may require higher emissions compared with the level which is optimal from the myopic point of view. An increase in the rate of discount typically reduces the optimal emission level.