Data and code for "The Role of Behavioral Frictions in Health Insurance Marketplace Enrollment and Risk: Evidence from a Field Experiment"

We experimentally varied information mailed to 87,000 households in California's health insurance marketplace to study the role of frictions in insurance take-up. Reminders about the enrollment deadline raised enrollment by 1.3 pp (16 percent) in this typically low take-up population. Heterogeneous effects of personalized subsidy information indicate misperceptions about program benefits. Consistent with an adverse selection model with frictional enrollment costs, the intervention lowered average spending risk by 5.1 percent, implying that marginal respondents were 37 percent less costly than inframarginal consumers. We observe the largest positive selection among low income consumers, who exhibit the largest frictions in enrollment. Finally, we estimate the implied value of the letter intervention to be $25 to $53 per month in subsidy dollars. These results suggest that frictions may partially explain low take-up for marketplace insurance, and that interventions reducing them can improve enrollment and market risk in exchanges. The attached code and data replicates results reported in this study.

本研究通过向加州健康保险市场（California's health insurance marketplace）的87000户家庭邮寄差异化信息开展实地实验，旨在探究摩擦因素在保险参保行为中的作用。针对参保截止日期的提醒，使该原本参保率偏低的群体的参保率提升了1.3个百分点（16%）。个性化补贴信息所产生的异质性影响表明，部分群体对项目福利存在认知偏差。结合带有参保摩擦成本的逆向选择模型来看，本次干预措施使平均支出风险降低了5.1%，这意味着边际参保者的医疗支出成本较边际内消费者低37%。我们在低收入群体中观察到了最为显著的正向选择，而该群体同时也面临着最为突出的参保摩擦问题。最后，经测算，本次信函干预的隐含价值为每月25至53美元的补贴额度。上述结果表明，摩擦因素可部分解释健康保险市场的低参保率问题，而针对性降低摩擦的干预措施能够提升参保率并优化保险交易所的市场风险结构。本研究附带的代码与数据可复现本文报告的全部实验结果。