This paper provides a review and assessment of the extensive literature on the political determination of environmental regulation. A promising theoretical literature has emerged relatively recently that provides models of the political interaction of government with various interest groups in the setting of environmental standards and the choice of regulatory instruments. A large empirical literature supports such models, finding evidence of the influence of interest groups but also evidence that net social benefits are often an important determinant of environmental policy choices. We then take up the issue of environmental federalism and the large and growing theoretical literature that addresses the competitive "race to the bottom." The paper concludes with a brief look at the evolution of environmental policy and finds that economics has come to play a growing role both in the setting of standards for environmental quality and in the design of regulatory measures.