UC Santa Barbara

This dissertation consists of three chapters that analyze the Affordable Care Act (ACA)’s Health Insurance Exchanges.

The first chapter analyzes plan choice in Covered California, the state-based Exchange of California. Specifically, I analyze three aspects of plan choice: partial year coverage, inefficient plan choice, and plan switching. With respect to partial year coverage, I do not find evidence that supports the common perception that special enrollment enrollees abuse the opportunity to obtain partial year coverage by signing up, getting treated, and then immediately dropping coverage. My analysis of inefficient plan choice shows enrollees to be making mistakes in plan choice by selecting plans that are dominated from the perspective of out-of-pocket spending. As for plan switching, I find the switching rate on Covered California to be close to 15 percent. My estimates from a mixed logit consumer choice model imply that household plan switching costs range from $1,000 to $5,000, depending on the age and income of households.

The second chapter is joint work with Richard Scheffler, Brent Fulton, and Sherry Glied and was published in the May 2016 issue of Health Affairs. The chapter analyzes how health plan, hospital, and medical group market concentration impacted the growth of health insurance premiums between 2014 and 2015 in two ACA state-based Exchanges: Covered California and NY State of Health. The results show that both states exhibited a positive association between hospital concentration and premium growth. Our results for health plan concentration differed between two states: it was positively association with premium growth in New York, but negatively associated with premium growth in California. We suggest the health plan concentration finding in Covered California may be the result of the Exchange selectively contracting with health plans.

The third chapter is joint work with Jon Gabel, Brent Fulton, Sam Stromberg, Matthew Green, Heidi Whitmore, and Richard Scheffler and was published in the January 2017 issue of Health Affairs. The chapter analyzes differences between “offered” premiums (a straight average across plan premiums) and “purchased” premiums (an enrollment-weighted average of plan premiums) on Covered California. We find purchased premiums are 10 to 15 percent lower than offered premiums and premium growth is lower by 2 percentage points when measured using purchased premiums as opposed to offered premiums.