A paper published by economics professors Enrico Moretti (UC Berkeley) and Gordon B. Dahl (UC San Diego) shows that men are less likely to stick around if the first child he has with a woman is female:
"We find that having girls has significant effects on marriage, shotgun marriage when the sex of the child is known before birth, divorce, child custody, and fertility. Taken individually, each piece of evidence is not sufficient to establish the existence of parental gender bias. But taken together, the weight of the evidence supports the notion that parents in the U.S. favour boys over girls."
Moretti and Dahl found that fathers were 3.1% less likely to be living with their family if the first-born in that family was a girl. Various factors make up this difference across several possible situations. Unmarried couples are less likely to get married if they have a girl as opposed to a boy. Divorces happen more frequently when the family has a girl, and in those cases, the father is less likely to get custody of a girl than a boy.
Moretti, who discussed his findings on the Freakonomics podcast, said that “over a 10-year period, [the gender difference] accounts for about 50,000 first-born daughters who are living without their father.”
Men, Moretti explains, have said that they favor having boys over girls in polls, while women are evenly split. There is also a cultural belief that boys need fathers as role models more than girls need fathers. Whether or not that’s true, the evidence shows that these 50,000 families with first-born daughters and an absent father have their income reduced by about 50%. While saying that single-parent households make half of what two-parent households do is not particularly profound, the impact of that fact has an obvious effect on the family’s mobility, opportunities and resilience to crisis. Poverty rates in these families increase by 30%.
Moretti and Dahl were able to further isolate the preference for sons by looking at what happens after a family has a child. Parents that had a girl were significantly more likely to have a second child than when the first born was a boy. One could counter that perhaps boys are more tiring and therefore the parents are less likely to add to their burden, but given the rest of the evidence, it seems likely that many of these families are hoping for a boy.
We can only hope that as the wage and power gaps between men and women close, that the these gender preferences will go away. Women, on average, are more empathetic and less violent than men. Are cultural attitudes ought to embrace these qualities.