A burgeoning literature in comparative politics has sought to incorporate i
deas into political analysis. In this article the authors categorize the ma
in ways in which this incorporation has occurred-ideas as culture, ideas as
expert knowledge, ideas as solutions to collective action problems, and id
eas as programmatic beliefs-and explicate the different assumptions about c
ausality and the permanence of ideas implied by these different frameworks.
This theoretical exercise is then applied to an empirical examination of e
ugenic ideas about sterilization and immigration and their influence on pub
lic policy in Britain and the United States between the world wars. Given t
hat ideational ideas were (broadly) equally powerful in both countries, the
cases provide a basis for shedding light on when and how extant ideational
frameworks influence public policy. Employing primary sources the authors
conclude that ideas remain powerful expressions of societal interests but d
epend upon key carriers to realize such expressions.