RT Journal Article SR Electronic T1 The Effects of Political Versus Actuarial Uncertainty on Insurance Market Stability JF RSF: The Russell Sage Foundation Journal of the Social Sciences FD Russell Sage Foundation SP 223 OP 242 DO 10.7758/RSF.2020.6.2.10 VO 6 IS 2 A1 Mark A. Hall YR 2020 UL http://www.rsfjournal.org/content/6/2/223.abstract AB Market stabilization is a critical regulatory challenge for the private insurance component of the Affordable Care Act (ACA). Initially ACA market instability was due largely to the actuarial uncertainty associated with new market conditions for which good actuarial data were lacking. Then, in 2017, just as actuarial uncertainty was abating, political uncertainty came into play, reactivating and compounding actuarial uncertainty. Agreement is widespread that some stabilization measures are needed to improve the functioning of the ACA’s market reforms. Based on documentary research at a national level and in-depth case studies in ten states, this study examines the role actuarial and political uncertainty have played in creating unstable market conditions and explores what measures state and federal lawmakers could take to improve market conditions.