[rich_sasha]

I certainly agree that parents being married is a bonus for the child. Apart from any strictly emotional considerations, married parents form a more stable platform for care and support during childhood. The fact that splitting up is so inconvenient probably keeps parents together through bigger disagreements than unmarried parents.

Now that I say it though, divorces are such major trauma that perhaps the tail risk counterbalances that benefit. I guess still not, but it's less clear.