An analysis of government data on married mothers ages 25 to 54, prepared for the Council on Contemporary Familiesseveral years ago, found that women whose husbands were in the lowest 25 percent of the male earnings distribution were most likely to stay home full-time.
The next most likely group of moms to stay home were all the way on the other end of the economic spectrum, married to husbands whose income places them in the top 5 percent of earners.
Paula England, a sociology professor at New York University and one of the paper's co-authors, said her other, more recent research also has shown that overall, more-educated moms are more likely to be employed. She thinks that's because they can get jobs that pay well enough and are interesting enough to make it worthwhile to work.
"Women who can't get good jobs anyhow – maybe not enough to cover their child-care costs or maybe not worth it in meaning – are the ones who are more likely to, if they have a husband, make the calculation (to stay home)," England said. "It really is kind of the opposite of what a lot of people believe."
She noted that there is that tiny slice of stay-at-home moms with very high-earning husbands. But across the board, she said, the better a job a mom can get, the more likely she is to be employed.
A Gallup analysis of 45,000 adult women released last year found that 75 percent of college-educated women with kids under 18 were working, compared with 48 percent of those moms with a high school degree or less. Gallup also found that 77 percent of moms with household incomes of $90,000 or more were working, compared with 45 percent of moms with household incomes of less than $24,000.
Rose Kreider, chief of the Fertility and Family Statistics Branch for the U.S. Census Bureau, said her research also suggests that instead of an "opt out revolution" involving highly educated married moms who want to leave the workforce, many moms who are younger, less educated, Hispanic and/or caring for very young children could be left out because they can't get a job that pays well enough to cover hefty child-care costs.
That's the situation stay-at-home mom Allicyn Willix found herself in last year, after she had her second child.
Willix, who lives in rural Bonnerdale, Ark., had just earned a college degree in English and gotten a job making $9.50 an hour working in a chiropractor's clinic when she found out she was pregnant.
She had planned to go back to work part-time after the baby was born, but scrapped those plans after realizing she'd have to make at least $11 an hour just to break even on child-care costs.
Willix, who is 28, loves that she gets to watch her 1- and 4-year-old kids grow and learn. But she would have preferred to return to her job.
"I did still want to work," she said.
Most women appear to feel that way. A Pew Research Center report released in March found that 32 percent of moms with children under age 18 think the ideal situation is to work full-time, while 47 percent said they would prefer to work part-time. Twenty percent said they would prefer not to work at all.
For Willix, it's partly because she misses the work itself, and the regular interaction with other adults. And it's partly because it's tough to live on her husband's income of $17 an hour.
Willix's parents help the young family out with food costs and provided financial backing for a home they are building. Meanwhile, an aunt is letting them rent a house she owns at a very low rate.
Nevertheless, Willix said they live paycheck to paycheck. They can only afford to drive to nearby Hot Springs twice a week, for things like visits to the library, and she can no longer send her 4-year-old to preschool.
Willix expects that she'll start looking for a job when her children get older and child-care costs become more reasonable. Meanwhile, she said she does appreciate that she is able to be home, teaching her children good lifelong habits.
"The good side is that I see my kids every day," she said.