Variation in Institutional Strength Steven Levitsky 1 and Mar´ ıa Victoria Murillo 2 1 Weatherhead Center for International Affairs, Harvard University, Cambridge, Massachusetts 02138; email: Levitsky@wcfia.harvard.edu 2 Department of Political Science, Columbia University, New York, New York 10027; email: Mm2140@columbia.edu Annu. Rev. Polit. Sci. 2009. 12:115–33 The Annual Review of Political Science is online at polisci.annualreviews.org This article’s doi: 10.1146/annurev.polisci.11.091106.121756 Copyright c  2009 by Annual Reviews. All rights reserved 1094-2939/09/0615-0115$20.00 Key Words political institutions, institutional development, weak institutions, enforcement, stability, developing countries Abstract Comparative research on political institutions has begun to turn from issues of formal institutional design to issues of institutional strength. Rather than assuming a tight fit between formal rules and political behavior, these studies examine how variation in the stability and/or enforcement of formal rules shapes actors’ expectations and behav- ior. This article explores the emerging research agenda on institutional strength. It disaggregates the concept of institutional strength into two dimensions—enforcement and stability—and it argues that institutions vary widely on both dimensions. The article then examines the sources of this variation and its implications for comparative research. It shows how recent research on weak institutions may be used to refine existing theories of institutional effects, design, and development, which should broaden the comparative scope of these theories. The conclusion exam- ines ways of developing comparative measures of institutional strength. 115 Annu. Rev. Polit. Sci. 2009.12:115-133. Downloaded from www.annualreviews.org Access provided by 52.73.204.196 on 05/10/22. For personal use only.