Consensus is growing about the fundamental principles underlying economic policy reforms. In addition, a series of recent comparative studies have increased scholarly understanding of the political conditions necessary for launching such reforms. Yet understanding of the factors that make reforms sustainable over the longer term is far less developed. A wide-ranging and unresolved debate continues over the roles played by institutions, politicians, interest groups, and the popular sectors. The influence of such groups tends to be marginal during the initial implementation of policies, a process involving an insulated group of technocrats. As the reforms proceed, the opposition of different societal groups to specific policies may have some impact but is less critical to the success or failure of the adjustment program than overall economic performance (see Geddes 1995). The primary strength of these groups is retrospective and collective: they can vote reforming governments out of office. Elections—and therefore voter behavior—are critical in sustaining economic reforms over the long term. Voters can reverse economic reform programs, and at times they do. Yet they also can play a major role in making programs more sustainable by legitimating their continuation at the ballot box.