This article reviews the recent literature on ex post evaluation of the impacts of the European Union (EU) Emissions Trading Scheme (ETS) on regulated firms in the industrial and power sectors. We summarize the findings from original research papers concerning three broadly defined impacts: carbon dioxide emissions, economic performance and competitiveness, and innovation. We conclude by highlighting gaps in the current literature and suggesting priorities for future research on this landmark policy. ( JEL : Q52, Q54, Q58)