Environmental regulations have consistently been found to spur innovation in "clean" technologies, with one significant exception. Past cap-and-trade programs have encouraged adoption of existing pollution control technologies, but had little effect on innovation. Several explanations have been...

The Clean Development Mechanism (CDM) provides some basic safeguards to ensure that HFC-23 reductions are additional, primarily aimed at establishing a realistic baseline scenario for HFC-23 projects. However, there have long been doubts about the additionality of HFC-23 projects (Wara,...

This paper presents a method for estimating treatment effects of regulations when treated and control firms compete on the output market. We develop a GMM estimator that recovers reduced-form parameters consistent with a model of differentiated product markets with multi-plant firms, and use...