STUDY: Number of Married Same-Sex Couples Up by 50 Percent in Three Years

As more and more states offer same-sex couples the right to marry, couples are taking advantage of this right -- the number of same-sex married couples in the U.S. increased by 50 percent between 2010 and 2013, according to a new study from the Williams Institute.

At the end of 2013, there were approximately 690,000 same-sex couples in the U.S., of which at least 124,000 and perhaps as many as 130,000 were married, says the institute's report, based on its analysis of the National Health Interview Survey for 2013, the first time the survey included a sexual orientation question. Comparing these numbers with data from other demographic studies, the Institute estimates the number of married same-sex couples increased by 50 percent over three years.

Other findings from the report, "LGB Families and Relationships: Analyses of the 2013 National Health Interview Survey," include the geographic distribution of married same-sex couples, with 39 percent living in the Northeast, where equal marriage rights have been available the longest. Twenty-eight percent live in the West, 21 percent in the Midwest, and 12 percent in the South. Nationwide, married same-sex couples are raising more than 30,000 children, according to the study.

Another new Williams Institute study, "LGBT Demographics: Comparisons Among Population-Based Surveys," finds that between 2.2 percent and 4 percent of U.S. adults, or between 5.2 million and 9.5 million people, identify as lesbian, gay, bisexual, or transgender. Younger people are more likely than older generations to identify as LGBT, and people in the Northeast and the West are more likely to do so than those in the Midwest or South.

The findings of these studies will be useful in political debates about LGBT rights, said Gary J. Gates, a Williams distinguished scholar and author of the studies. "Courts, legislatures, and voters continue to debate high-profile policy issues including marriage and parenting rights for same-sex couples along with economic and health disparities associated with discrimination and stigma toward LGBT individuals," Gates said in a press release. "The availability of new data sources that include identification of LGBT respondents allows us to better inform those debates with critical information about the demographic characteristics of LGBT individuals and their families."

The Williams Institute, a think tank based at the University of California Los Angeles, School of Law, is dedicated to conducting independent research on legal and public policy issues related to sexual orientation and gender identity.