Over at the Power Line blog, my former AEI colleague Steve Hayward notes that the first same-sex divorce in the state of Indiana occurred a couple of weeks ago. Will gay couples end up divorcing at higher rates than straight couples? Steve justifiably wonders whether American social scientists will be willing to study the durability of same-sex relationships, given the witch-hunting of Mark Regnerus and others who have published data that paint such relationships in a negative light.
Since Steve also cites the kerfuffle over my own politically incorrect research (on immigration), I might as well be the one to point to some of the studies on same-sex divorce in northern Europe, where gay unions have been legally recognized for much longer than here in the U.S. Although the research is preliminary, the general finding is that, yes, same-sex couples are more likely to divorce than opposite-sex couples.
The best study I've seen focused on Scandinavia, where same-sex civil unions - essentially marriages in everything but name - have been legal for about two decades. The authors had access to population-level administrative data that generated a sample size of over 1,500 same-sex unions. After controlling for age, region, country of birth, education, and duration of the partnership, male couples in Sweden were 35 percent more likely to divorce than heterosexual couples, and lesbian partners were over 200 percent more likely to divorce. Whether the couples had children made little difference in the relative rates.
Studies of unmarried "cohabiter" couples are less informative - I'm not convinced that platonic roommates have been adequately excluded from the category of "couples" - but the results point in the same direction. In the Netherlands, for example, researchers examined tax and population records to track the relationship status of filers, including 731 same-sex couples. The dissolution rate for unmarried same-sex couples was more than double the rate for unmarried opposite-sex couples.
A small study of British cohabiters found that, compared to married heterosexuals, opposite-sex cohabiters were 2.75 times as likely to break up within five years, whereas same-sex cohabiters were 5.25 times as likely as to end their relationship in that time.
There are hints of similar results in the American literature, usually found below the headlines of studies with small sample sizes. But, down the road, will researchers jump at the chance to publish large-scale comparisons here in the U.S.? And will they suggest their results have policy implications? Sadly, in this political climate, it might depend on which way the results come out.