They tend not to do much more, though, and I'm not sure that offsets the incredible additional burden of raising small children without a safety net, especially considering the terrible long-term effects of not having stable housing, good nutrition, or a safe neighborhood and home environment (since poor kids seem to be disproportionately at risk of abuse by stressed-out and underequipped mothers or stepfathers/boyfriends) when kids are young. A man without kids doesn't have those worries.