British Journal of Political Science


On the Interpretability of Law: Lessons from the Decoding of National Constitutions

James Melton, Zachary Elkins, Tom Ginsburg and Kalev Leetaru *


An implicit element of many theories of constitutional enforcement is the degree to which those subject to constitutional law can agree on what its provisions mean (call this constitutional interpretability). Unfortunately, there is little evidence on baseline levels of constitutional interpretability or the variance therein. This article seeks to fill this gap in the literature, by assessing the effect of contextual, textual and interpreter characteristics on the interpretability of constitutional documents. Constitutions are found to vary in their degree of interpretability. Surprisingly, however, the most important determinants of variance are not contextual (for example, era, language or culture), but textual. This result emphasizes the important role that constitutional drafters play in the implementation of their product.

(Online publication October 09 2012)


*  Department of Political Science, University College London (email:; Department of Government, University of Texas at Austin; Law School, University of Chicago; and Institute for Computing in the Humanities, Arts, and Social Science, University of Illinois at Urbana-Champaign, respectively. The authors wish to thank Manuel Balán, Sara Birch, Abby Blass, Rui de Figueiredo, Brian Gaines, Ran Hirschl, Jeffrey Isaacs, Simon Jackman, Roger Noll, John Sides and two anonymous reviewers for helpful comments. They have appreciated financial support from the National Science Foundation (SES 0648288) and the Cline Center for Democracy. James Melton thanks the IMT Institute for Advanced Studies, Lucca, for additional financial support. Replication data are available on the Comparative Constitutions Project website: