OK, you probably already read Steven Landsburg on Slate.com. But this article of his is too good a link to pass up. It turns out that divorce is considerably more likely when the child is a girl, rather than a boy. Here are two choice bits:
In the United States, the parents of a girl are nearly 5 percent more likely to divorce than the parents of a boy. The more daughters, the bigger the effect: The parents of three girls are almost 10 percent more likely to divorce than the parents of three boys. In Mexico and Colombia the gap is wider; in Kenya it’s wider still. In Vietnam, it’s huge: Parents of a girl are 25 percent more likely to divorce than parents of a boy.
Here is another:
Take a typical unmarried couple who are expecting a child and have an ultrasound, which more often than not reveals the child’s sex. It turns out that such couples are more likely to get married if the child is a boy. Apparently, for unmarried fathers, the prospect of living with a wife and a son is more alluring than the prospect of living with a wife and a daughter.