It seems like the causal link on those statistics might be wrong. Sure, happy families might do better then divorced single parents. But how do unhappy couples forced to stay togather compare to single parents?
That's an interesting hypothesis. How would you do a longitudinal study on which couples are forced to stay together? I think we skipped some empirical work and jumped straight to a narrative in the way we reformed family structure over the decades.
Ironically, women and children (especially boys) seem to be the hardest hit, at least statistically. This is distressing since they were supposed to be the reason we started rethinking family structure in the first place.
Regardless, the census statistics are for all single households versus all married households. The never-married are also included in the statistics, so trapped-in-a-relationship certainly doesn't always apply.
Here's an LA Times column breaking down a few more studies:
