This is an essential insight, given the dominant narrative about marriage, single-parenthood and poverty rampant not just among the usual suspects of the right but among many liberals.
Matt Breuning @ Demos:
I see it often claimed that the high rate of child poverty in the US is a function of family composition. According to this view, the reason childhood poverty is so high is that there are too many unmarried parents and single mothers, and those kinds of families face higher rates of poverty. The usual upshot of this claim is that we can't really do much about high rates of childhood poverty, at least insofar as we can't force people to marry and cohabitate and such.More here.
One big problem with this claim is that family composition in the US is not that much different from family compositions in the famed low-poverty social democracies of Northern Europe, but they don't have anywhere near the rates of child poverty we have.
A number of studies have tested this family composition theory using cross-country income data and found, again and again, that family composition differences account for very little of the child poverty differences between the US and other countries...