Right. Even when the kids are old enough to be in school full-time, there's still lots of "free" labor that's being left out of the GP's reasoning. A single p

Right. Even when the kids are old enough to be in school full-time, there's still lots of "free" labor that's being left out of the GP's reasoning. A single parent's earning power would need to be significantly higher than a 1950's man's earning power and/or they'd need the same earning power with significantly more non-work hours per week.