Researchers at Boston College reviewed how much motherhood costs women in Social Security benefits. They found that, among other things, mothers with one child receive 16 percent less in benefits than non-mothers, and each additional child reduces benefits by another two percent.
"The motherhood penalty is almost negligible among women receiving spousal benefits," the researchers stated, "but mothers who receive benefits on only their own earnings histories see significantly lower Social Security income."
Before jumping to any conclusions that the Social Security Administration is sexist or biased, Carrie Lukas of the Independent Women's Forum says the figures related to what she calls an "arbitrary" formula.
"It has some strange factors to it and that in some ways it's actually titled towards stay-at-home moms," she says. "If you're a married woman and you don't work, you can get 50 percent of what your husband's benefits are, and you earned that even though you didn't contribute to Social Security during your own lifetime."
If a woman worked but earned only half of her husband's earnings, Lukas continues, she will get the same benefits as a woman who never paid in to Social Security.
Lukas says she remains interested in moving towards a savings-based retirement system.
"Or just make it so some of those unfairnesses are ironed out and it truly becomes something that is linked exclusively with how much you put in," she says.