The Political Geography of ACA Marketplaces: How Political Behavior Can Help Explain Where the ACA Works, and Where it Doesn't

Abstract

Political partisanship can influence whether individuals enroll in government programs. In particular, Republicans, ceteris paribus, are less likely to enroll in Affordable Care Act individual marketplace insurance than Democrats. The logic of adverse selection suggests low uptake amongst Republicans would generally put upward pressure on marketplace premiums, especially in geographic areas with more Republican partisans. I provide empirical evidence that insurers have increased marketplace premiums at higher rates in areas with more Republican voters. A variety of robustness checks indicate that a meaningful portion of the variation in premium growth is driven by partisanship and not confounding factors. This finding suggests political polarization threatens the successful implementation of policies that rely on high levels of citizen participation.