[Update: I think these calculations of the dissolution rate of same-sex marriage are too low by a factor of 2; see discussion here.]
This news article by Isha Aran, titled, “Same-Sex Couples Less Likely to Get Divorced Than Straight Couples,” is an accurate summary of this recent research report from M.V. Lee Badgett and Christy Mallory, who write:
Now that same-sex couples have the ability to marry or enter some other form of legal relationship in many states, we also see that couples sometimes dissolved those legal relationships. Administrative data from two states shows that same-sex couples end their marriages at a rate of 1.1% annually, on average, and an average of 1.6% of couples dissolve their legal relationships if a broader set of states is included. This rate is slightly lower than the annual rate of divorce among married different-sex couples.
In particular:
The table presents data collected from New Hampshire and Vermont [the only two states that reported same-sex divorce data] and shows that a total of 5.4% of New Hampshire couples and 3.6% of same-sex couples in Vermont divorced in the first four years or so of marriage equality. That corresponds to an average rate of 1.1% annually for the two states. This is slightly lower than the annual rate of divorce among different-sex couples, which is about 2% annually.
Really they should compare to just the divorce rate in New Hampshire and Vermont, not the whole nation, but I don’t think the divorce rate in those states varies enough from the U.S. average for this to make much of a difference.
Also, to be parallel, they should compare to the divorce rates in the first four years of marriage, not the overall divorce rate. But I suspect that the divorce rate is actually higher in those first four years (or, if lower, not much lower than the average divorce rate), so, again, I think their comparison still holds.
It’s just two states, though. Badgett and Mallory report that data remains sparse:
In early 2014, the Williams Institute collected administrative data on marriages, civil unions, and domestic partnerships of same-sex couples in the 23 states that offered these statuses at the time data collection began. Two states provided data on divorces: New Hampshire and Vermont. Six states provided data on civil union and domestic partnership terminations: California, D.C, New Hampshire, New Jersey, Washington, and Wisconsin.
The reported dissolution rates vary a lot among these six states, with the highest being Washington state, at 5 percent per year. But it’s hard to know what to make of this number as it corresponds to “civil union/domestic partnership,” not marriage.
The other thing I wonder is how this will play out over time. The first wave of same-sex marriage is not necessarily typical of what will happen in future years, and in other states. So it will be interesting to see this go forward. It would also be interesting to see the age distribution of the newlyweds. I’d expect that in the first years of same-sex marriage we’d see a lot of older couples and then the average age of marriage would settle down to a lower level, comparable to that of traditional wives and husbands.
Finally, Aran reports that “female couples make up 51% of all same-sex relationships, but 64% of legally formalized relationships” but the data in the linked report does not separate out the dissolution rate by sex (a data partition that can be done with same-sex marriage but not, of course, with traditional marriage data). Many more interesting things to look at.