The Separation of Powers and Policymaking in the US States

ABSTRACT Do the separation of powers dynamics in the United States affect policymaking outcomes? Scholars and observers of national politics have long expected that they do, but since there has been little meaningful variation in the constitutional separation of powers system, it has been difficult to conduct empirical assessments. We turn to the American states, were there is variation from state to state in separation of powers institutions. Drawing on a dataset of hundreds of thousands of bills introduced to state legislatures, and the case of North Carolina giving its governor veto power in 1997, we find evidence that greater separation of powers institutions generally relate to less legislative productivity and less partisan lawmaking. However, these findings are meaningfully conditioned by the presence or absence of divided government, and there is some variation from state to state.