When Do Ideas Matter?

The field of comparative politics has begun to take seriously the role of ideas in politics, but to date this interest has not clearly specified the conditions under which ideas influence public policy. The author develops an integrated framework that shows ideas about policy goals and instruments are most influential when they do not attract substantial opposition from voters and interest groups and when political institutions concentrate decision-making authority. The author tests this framework by examining the fates of three ideas, facing different degrees of societal opposition and concentrated authority, adopted by the first Thatcher government in Britain.