Measuring State Capacity in the U.S. States

Abstract

Political scientists recognize the importance of state capacity for issues such as peace, economic development, public health, and regime stability. Researchers have not agreed on how to measure state capacity. Crucially, many metrics inadvertently conflate strategic policy choices or policy liberalism with capacity. Furthermore, common cross-national measures do not work at subnational levels. American politics literature has additionally mostly overlooked subnational variations in state capacity. We propose a subnational measure of state capacity that compares all U.S. states from 2000 to 2019. Using a Bayesian factor analytic model, we model state capacity as a reflective, latent trait. Our measure draws on shared policy goals to identify states' latent ability to deliver on policy, thus distinguishing the capacity to act from political preferences. We then run a series of validation tests to establish construct validity and to explore the political forces that have impacted subnational capacity in the American context.