6 April 2017This chapter discusses the theoretical and empirical literature analyzing the effects of democracy and political institutions on environmental policy and quality. Current research indicates that the effect of democracy on the environment is not unambiguous. Within democracies, environmental quality and policy outcomes are affected by the existence of specific political and legal institutions. These institutions play a pivotal role, and include parliamentary and presidential-congressional governance structures; majoritarian and proportional electoral systems; unicameral and bicameral systems; open and closed party list voting systems, and civil and common law legal origins. The degree of political competition in democracies also affects environmental policy outcomes.