An Iowa State University economist says the popular notion that stay-at-home mothers do the work that’s equal to a six-figure salary just doesn’t add up. Wallace Huffman studies Labor Department data.

and says he has some general idea about how the six-figure salaries are computed — but says he still believes those estimates are inflated. He looked at what it would cost to hire someone outside the home to do the work.

Huffman says part of the work around the house that you could get domestic servants to do — like cleaning or simple repairs — you could hire someone to do for around 10 to 12 dollars an hour. He says that wouldn’t generate a six figure income in annual pay. Mothers often take care of sick kids, but Huffman says even that home healthcare work wouldn’t push their salaries way up.

Huffman says they’re not formally trained, or licensed as a nurse or medical doctor — and even if they were a "quasi nurse" — they’d make around 20 dollars an hour. He says a fulltime job is roughly 2,000 hours a year, and at the 20 dollar-an-hour rate, that would bring in only $40,000-a-year. Huffman says women already in the labor force now average working about 36 hours a week, so it’s hard to make the numbers add up to a six-figure salary.