Same-sex marriage and health insurance coverage decisions by employers

Project Outcomes Statement

This award provided new descriptive and evaluative evidence regarding same-sex marriage and employer choices about health insurance benefits by using employer surveys that contain information on employer choices about health insurance offerings to employees. It also relied on a novel linkages among the employer survey, tax records, and other administrative records to understand the geographic distribution of an employer's workforce. The award involved leveraging the fact that some parent firms had workers primarily located in states without legal same-sex marriage prior to the 2015 Obergefell vs. Hodges nationwide legal same-sex marriage decision, while other parent firms already had experience with workers in different policy regimes regarding legal same-sex marriage.
The award led to several findings. First, among employers offering any health insurance coverage to employees, the share of private sector employers that offered same-sex domestic partner (SSDP) benefits was approximately 7 percentage points higher than the share who offered DSDP benefits in the year prior to nationwide legal SSM. Second, immediately following the 2015 Supreme Court ruling extending nationwide marriage equality in Obergefell, the share of employers offering SSDP benefits fell sharply. These reductions were sustained through 2019, and no effect was observed on the offer rate for DSDP health benefits, on the offer rate for unrelated benefits such as dental and vision coverage, or on the average premium for single coverage. Third, there is no relationship between the pre-existing legal environment regarding legal access to SSM when measured by the location of the sampled establishment and the magnitude of the decline in offers of SSDP benefits.
Despite this, the award also found that there are very large differences in the likelihood of offering same-sex domestic partner coverage in 2013 and 2014 across parent firms with differing amounts of workforce exposure to legal same-sex marriage: parent firms with a significant share of workers with legal access to same-sex marriage by 2014 had more than double the rate of SSDP coverage offers than parent firms whose workers were nearly all in states without legal SSM. Moreover, the award estimated that legal SSM was associated with significant reductions in the likelihood of offering SSDP benefits, an effect on the order of 5.5-12.6 percentage points. These effects are unique to SSDP benefits: there was no similar effect on different-sex domestic partner benefits or other unrelated benefits such as dental or vision coverage.
This award's results are the first to show that legal SSM was associated with significant reductions in the likelihood of SSDP benefits and demonstrate the importance of both the local and national legal environments in contributing to employer decisions about domestic partner benefits.