Economic costs come not from same-sex households but from single-parent households.
The 2010 Census reported some 0.77 percent of households in same-sex relationships, and the best studies on the matter pinpoint no measurable economic consequences for good or ill in such arrangements. The condition of same-sex marriage or household arrangements possesses no economic consequences.
However, the debate itself does have consequences because it crowds out honest deliberation on the real problems of collapsing families. These problems carry with them enormous fiscal and social costs that demand deep attention.