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 Y ork, New Y ork 10027; email: [email protected] 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 forma l institu tional design to issues of institu tional strengt h. 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 compar ativ e sco pe of the se the ori es. The con clu sion exam- ines ways of developing comparative measures of institutional strength. 115 A n n u . R e v . P o l i t . S c i . 2 0 0 9 . 1 2 : 1 1 5 1 3 3 . D o w n l o a d e d f r o m a r j o u r n a l s . a n n u a l r e v i e w s . o r g b y M a r i a M u r i l l o o n 0 6 / 0 2 / 0 9 . F o r p e r s o n a l u s e o n l y . Click here for quick links to Annual Reviews content online, including: Other articles in this volume Top cited articles Top downloaded articles Further ANNUAL REVIEWS