Measuring Legislative Accomplishment, 1877–1994


  • The authors would like to thank: R. Douglas Arnold, David Brady, Ira Katznelson, David Mayhew, Mat McCubbins, Nolan McCarty, Rose Razaghian, Doug Rivers, Ken Scheve and participants of the Center for the Study of Democratic Politics at Princeton University, participants of the American politics workshops at Columbia University, Northwestern University, and MIT, Cal Tech's political economy workshop participants, and participants in the History of Congress II Conference at Stanford University for helpful suggestions and reactions. Lapinski thanks the Russell Sage Foundation's Scholars in Residence Program for a condusive environment for research and writing as well as the National Science Foundation (SES 0318280) and Columbia University's ISERP and the Institution for Social and Policy Studies at Yale University for financial assistance for the data collection effort. Assistance in data collection has been provided by many individuals, particularly helpful were Eldon Porter, Andrew Roach, Sylvia Wu, Don Phan, Cleve Doty, and Daniel Clemens of Yale University, Melanie Springer and Christine Greer of Columbia University, and Nancy Danch of the Bobst Center for Peace and Justice at Princeton University.

Joshua D. Clinton is assistant professor of politics, Princeton University, 036 Corwin Hall, Princeton, NJ 08544-1012 ( John S. Lapinski is assistant professor of political science, Yale University, P.O. Box 208209, New Haven, CT 06520-8209 (


Understanding the dynamics of lawmaking in the United States is at the center of the study of American politics. A fundamental obstacle to progress in this pursuit is the lack of measures of policy output, especially for the period prior to 1946. The lack of direct legislative accomplishment measures makes it difficult to assess the performance of our political system. We provide a new measure of legislative significance and accomplishment. Specifically, we demonstrate how item-response theory can be combined with a new dataset that contains every public statute enacted between 1877 and 1994 to estimate “legislative importance” across time. Although the resulting estimates and associated standard errors provide new opportunities for scholars interested in analyzing U.S. policymaking since 1877, the methodology we present is not restricted to Congress, the United States, or lawmaking.