We introduce a "smart" cap and trade system that eliminates the welfare costs of asymmetric information (“uncertainty”). This cap responds endogenously to technology or macroeconomic shocks, relying on the market price of certificates to aggregate information. It allows policy makers to...

We develop a 2-period emission trading model for a stock pollutant with demand shocks resolving over time. We find precise conditions for efficiency of a stabilization mechanism where cumulative available permits decrease with excess supply in early periods. Our model describes the stabilization...

"Prices versus quantities" (Weitzman 1974), a hugely influential paper, is widely cited (and taught) in current debates about the best policy to reduce greenhouse gas emissions. The paper's criterion for ranking policies suggests that technological uncertainty favors taxes over cap and trade....