The economics of (plural) marriage

Laura McKenna posts on the polygamy case:

The details of the raid on the Polygamist cult in Texas are coming out. It's horrifying. Girls married off to men when they hit puberty. Boys taught to be sexual predators. There's the strange clothing requirements. The cult got rich out of gangs of unmarried mothers getting welfare. Some 400 kids may have to go into foster care, and the system is overwhelmed. The kids are going to require serious counseling. The Texas courts may rule that polygamy is inherently abusive to children, which the AZ and UT courts have never ruled. Some links here, here, here, and here.

This brings to mind an argument I once had with Bryan Caplan at lunch; polygamy, he said, should be good for women, since it increases demand for them, and thus enhances their bargaining power.

In theory perhaps, I said, but in practice, the only cultures that practice it are also ones that radically restrict womens' freedom.

Now I think that those two things may be linked: that polygamy in fact does enhance the bargaining power, and thus any society that practices it ends up radically restricting their rights in order to counteract that power--thus, twelve year old girls married of to sixty year old men.