An increasing number of global policy regimes are intended to influence international business practices, but their effectiveness is uncertain. This article presents a conceptual framework for understanding the effectiveness of regimes, with seven propositions. The case of the evolving global anticorruption regime is described and used to test the propositions. Two key conclusions are (a) the difficulty of the problem being addressed is a key factor in limiting regime effectiveness and (b) this problem, as well as others, can be addressed (...) in part by careful development of formal regime policies. Implications for scholarship and practice are presented. (shrink)