Reader Brett, posed the question to me does it cost more to have a son or daughter. I have a 14 month old daughter, so I'm starting to gather data. This paper by Lunberg and Rose attempts to answer that question by looking at how households with one daughter or son spend money. In short they find for most things spending is the same. However, families with sons live in bigger houses and spend more on personal care services (eg hair cuts), while families with daughters spend more on clothes.
The conclusion of the paper of the paper tries to figure out the results for boys, since the girls results seemed pretty intuitive. The authors argue that perhaps boys need more space or that families want to have boys live in better neighborhoods to avoid risk. They also suggest mom spends more on hair cuts because in their words "This result suggests some redistribution from fathers to mothers, and is consistent with the hypothesis that boys directly increase their father’s utility, relative to girls."
I'm surprised Lundberg writes after seeing this, I'm not sure her husband could be much happier.