I think it does all boil down to finances - two incomes may be ideal and for some, even necessary - but among many of the more blue collar workers, how much of that "second" income do they see? I'm much closer myself to the blue collar set than those princeton grads and I will tell you this: once a family really looks into how much it costs to send two people to work: Daycare, lunches, gas, work clothes, etc often the numbers just don't add up to equal a really significant bonus to have both parents work. If you make, say, 50K+ a year, you could bring home enough to make it worthwhile, but in the 18-30K set, not so much.

My best friend, who lives in a low cost of living area (rural Arkansas) is the main breadwinner for her family, making about 28K a year. Her husband was staying home with the baby, but has gone back to work, forcing them to put the baby in daycare. Since that time their little girl has got chronic ear infections, has become resistant to even the most potent (and pricey) antibiotics, and will now have to have tubes put in her ears. If you factor in the time missed from work, the co-pays for doctor visits and prescriptions, and the upcoming surgery, they are at a loss, having gained nothing. They are now instead trying to work out their schedules so that one of them can be at home with the little one all the time. They only have the one child; imagine what it must be like for families like theirs who have more than one child in daycare, getting sick, and all that.

I'm all for having women in the workforce, but when you look at this opt-out phenomenon, especially in the mid to lower classes, it often makes the most sense financially. I don't see it as losing an income so much as losing a long list of expenditures and gaining some quality time with your children.