Looking into polygyny :: The Undercover Economist
Just in time for Valentines Day

Read the whole thing. My favorite bits:

A lot of the knee-jerk reactions against polygyny are from people who can't add up.

In a society with equal numbers of men and women, each man with four wives gives women the additional pick of three men - the poor saps whose potential wives decided they'd prefer one quarter of a billionaire instead. In the Sahel region of Africa, half of all women live in polygynous households. The other half have a good choice of men and a lot more bargaining power.
. . .
A little over one in 100 American men are in prison - but there are several states where one in five young black men are behind bars. Since most women marry men of similar age, and of the same race and the same state, there are some groups of women who face a dramatic shortfall of marriage partners.

Economist Kerwin Charles has recently studied the plight of these women. Their problem is not merely that some who would want to marry won't be able to; it's that the available men suddenly have more bargaining power.
. . .
The women's response makes sense: girl power. The women affected do everything to make the most of single life, including staying at school for longer and hunting for more paid work. The American prison system hasn't left them much choice.
. . .
polygyny's reputation needs to be rehabilitated. Nevertheless, I am resolutely against its introduction. We men are downtrodden enough already.

UPDATE: The Weather Girls have this to say.