Legislative Effectiveness in the American States

We develop State Legislative Effectiveness Scores (SLES) for state legislators across 97 legislative chambers over recent decades, based on the number of bills that they sponsor, how far those bills move through the lawmaking process, and their substantive importance. We assess the scores through criterion and construct validation and reveal new insights into effective lawmaking across legislators. We then offer two illustrations of the immense opportunities that these scores provide for new scholarship on legislative behavior. First, we demonstrate greater majority-party influence over lawmaking in states featuring ideological polarization and majority-party cohesion, and where there is greater electoral competition for chamber control. Second, we show how institutional design choices—from legislative rules to the scope of professionalization—affect the distributions of policymaking power from state to state.