DIvorce rates higher when gay marriage banned

From the über-pollsters at FiveThirtyEight:

Over the past decade or so, divorce has gradually become more uncommon in the United States. Since 2003, however, the decline in divorce rates has been largely confined to states which have not passed a state constitutional ban on gay marriage. These states saw their divorce rates decrease by an average of 8 percent between 2003 and 2008. States which had passed a same-sex marriage ban as of January 1, 2008, however, saw their divorce rates rise by about 1 percent over the same period....

The differences are highly statistically significant. Nevertheless, they do not necessarily imply causation. The decision to ban same-sex marriage does not occur randomly throughout the states, but instead is strongly correlated with other factors, such as religiosity and political ideology, which we have made no attempt to account for. Nor do we know in which way the causal arrow might point. It could be that voters who have more marital problems of their own are more inclined to deny the right of marriage to same-sex couples.

There is, however, probably now enough data on this subject to engage in more sophisticated longitudinal studies on this subject (more sophisticated than I have engaged in here), which might produce more robust conclusions. Although only Massachusetts has affirmed gay marriage for any length of time, the difference between the states which have banned it constitutionally versus statutorily may be worth examining, as the former represents a significantly more confident assertion about the nature of state-sanctioned marriage. At the very least, I would be surprised if there were any statistical evidence that interpreting the right of marriage to apply to same-sex couples would be injurious to heterosexual couples in any material way.