Key findings of two studies, each the first of its kind, found that lesbian couples earn about 68 percent of what gay male couples make and gay male couples are the least likely to break up among lesbian and heterosexual couples.
A new Urban-Brookings Tax Policy Center report studies marriage patterns after the Obergefell v. Hodges Supreme Court decision in 2015, which legalized same-sex marriage nationwide. The report claims .48 percent of all joint filers were same-sex couples, about 250,450 in 2015.
Adam Looney, a fellow with Urban-Brookings who worked on the report, said this is the first time a study has recorded the major changes after the Supreme Court's ruling, including the number of same-sex filers.
"There is very little information as to how the Supreme Court's ruling affected the filing or number of same-sex marriages," he said. "Our goals were in the midst of this social change to provide documentation of people who were affected by the changes and the characteristics of same-sex people and where they live."
Looney said although the findings were thought to be true for a long time by many people, the report provides researched documentation. He found the most striking findings to be the geographic concentration of same-sex married couples in metropolitan areas and the income gap of lesbian couples compared to gay male couples.
When comparing the incomes of all joint filers nationwide between the ages of 25 and 55 in 2015, females in same-sex relationships earned about 68 percent of what male-male couples earned. That's roughly 10 percentage points less than the widely cited "wage gap" that women earn on average, $0.78 for every $1 men earn. As well, household income for male same-sex couples was, on average, higher than household incomes of different-sex couples.
Other key findings found the highest portion of same-sex filers live in states that had legalized same-sex marriage prior to 2013, in coastal states, and in certain metropolitan areas.
To read the tax study, go to http://www.taxpolicycenter.org/publications/same-sex-married-tax-filers-after-windsor-and-obergefell/full.
Breakup study
Another study, conducted by the Williams Institute at the UCLA School of Law, compared relationship breakups among same-sex and heterosexual couples over a 12-year period in Vermont, where same-sex marriage has been legal since 2009, the fourth state to do so.
It found women in same-sex relationships were twice as likely as male, same-sex couples and 1.5 times as likely as straight couples to end their relationships.
"Other studies on heterosexual couples have found that women have higher standards for relationship quality than men," study author Esther Rothblum, a professor of women's studies at San Diego State University and visiting scholar at the Williams Institute, said in a statement. "We suspect that similar dynamics may be at play with the lesbian couples in our study, leading to the higher dissolution rate. At the same time, we found that older couples were less likely to break up, and having children had no impact on the break-up rates."
This is the first time a study has compared relationship breakups among same-sex and heterosexual couples over a 12-year period in the same geographic area. Another author of the study, Kimberly Balsam, a clinical psychologist and psychology professor at Palo Alto University, said the study was important because it "is crucial in combating stereotypes about same-sex couples and can inform policy and program development to support healthy relationships for all couples."
The Williams Institute report was published in Couple and Family Psychology: Research and Practice.