Two University of Washington economists found that an unmarried mother is 42 percent more likely to marry the father if the child is a boy.
The study by economics professor Shelly Lundberg and associate professor Elaina Rose will be published in the May issue of the journal Demography.
"It may be that parents just feel more strongly that a boy needs a father around," Rose said, "or it could be that it's easier to find a husband if your child is a boy."
The findings build upon previous research by the same authors showing that fathers of sons spend more money on their families and work harder at their jobs than fathers of daughters. And other researchers have found that couples with sons are less likely to get divorced than those with daughters.
The new Demography study is the first, Rose and Lundberg said, to document how gender affects the nearly one-third of America's children born outside of wedlock.
Using data from the national Panel Study of Income Dynamics, which yielded a scientific sampling of 600 children born to single mothers, the UW researchers found that the unmarried mothers of boys were 11 percent more likely to find a husband than those with girls. When it came to tying the knot with the child's biological father, the boy-girl gap rose to 42 percent.
Lundberg and Rose speculate that some parents see boys as especially needing a male role model, or that some men simply value a family with a male offspring more highly.
"Either fathers are more important to boys," Lundberg said, "or boys are more important to fathers."
Either way, one effect is that girls are more likely than boys to grow up in single-parent households. Since children without married parents are more likely to live in poverty, getting fathers more involved is a major concern to the White House and other policymakers, said Lundberg, who is director of the UW's Center for Research on Families.
"These studies are telling us something," Lundberg said, "about what it takes to engage fathers in the family."
Many unmarried dads, of course, remain active in their children's lives, and the U.S. census has counted growing numbers of parents who live together without a marriage license. Rose and Lundberg are teaming up with a sociologist to study more closely the circumstances that prompt parents to marry, as well as how a very young child's gender affects fathers.
In the meantime, the researchers can only speculate on why having a boy gives mothers more "success" in the marriage market - especially in attracting biological fathers to the altar.
"Some men probably see a biological son as their immortality," Rose said. "It's a little 'me.' "
For more information, contact Lundberg at 206-543-6149 or firstname.lastname@example.org
--NOTE: May 5-7 she can be reached at Brown University 401-863-3875, or Rose at 206-543-5237 or email@example.com (NOTE: She will not be reachable May 5-7). The study is posted at: www.econ.washington.edu/econprelim/users/lundberg/transmar.pdf