Girls lead to divorce?

Apparently, some econometricists have found a striking gap in the divorce rate that depends on the number of children a couple has. The more children, the greater the disparity--6 percent for one girl versus one boy, 8 percent for two, 10 percent for three, and 13 percent for four.

It makes one wonder what the cause of the discrepancy is. [Only partially facetiously, one might say that this argument gives the lie to the ubiquitous break-up excuse, "It's not you, it's me."]