dirty innovation and production; (ii) optimal policy involves both “carbon taxes” and research subsidies, so that excessive … the switch to clean innovation under laissez-faire when the two inputs are substitutes. Under reasonable parameter values …

Environmental regulations have consistently been found to spur innovation in "clean" technologies, with one significant … effect on innovation. Several explanations have been offered, including secondary market failures and a lack of polluter …, contrary to past experience, encouraged innovation rather than adoption. I discuss how these contrasting findings can be …