This paper draws on a number of recent studies to shed light on several policy issues raised by the impact of environmental policies on technological innovation. First, to what extent does induced innovation raise the overall net benefits to society from environmental policies? Second, how does induced innovation affect the appropriate choice among alternative environmental policy instruments? Third, how does it affect the optimal stringency of environmental regulations? Fourth, should environmental policies be supplemented with additional policies to promote innovation, such as research contracts or prizes for new technologies?