The Right Coast

February 10, 2005
More Armchair Musings on Polygamy vs. Monogamy
By Gail Heriot

Polygamy existed for a long time (and in some places in the world continues to exist). What does it have to recommend itself?

It seems to me that polygamy is most likely to emerge as the dominant marital institution in cultures in which (1) A high birth rate would be seen as desirable; (2) Men tend not to remain in one place or to accumulate sufficient property to support a family until they are somewhat old ... say 30 or older; (3) Women (or should I say girls) are sufficiently mature to fulfill their responsibilities as wives and mothers at a significantly younger age ... say 16 or older; and (4) Because young people die from disease, accident and war at a fairly high rate, there are a lot more women (or girls) of marriageable age than there are men of a marriageable age. Under these circumstances, by refusing to "waste a womb" just because there isn't a marriageable man for each woman capable of bearing a child, polygamy will produce a higher birth rate than monogamy, and it will increase the chance that if a young mother dies, her child will have a stepmother already in place to help out. Moreover, the men who are getting edged out of the marriage market under such a system, don't realize they have been edged out. They think their time is coming in the future (though many of them turn out to be wrong because they die before they get a chance to marry.)

Of course, (mercifully) this is not the world we live in, and maybe that's part of why polygamy has so few advocates today. Few argue that the focus of our "marriage policy" ought to be to produce the highest birth rate possible. And even if they did, modern Western nations do not have the pyramid shaped-demographic (with lots of young people, fewer middled-aged people and fewer still old people) that used to characterize societies everywhere. Polygamy thus has no advantage over monogamy in its effect on the birth rate. Indeed, if polygamy were to somehow catch on, its most significant effect would be to create a pool of "left out" men--probably not an effect that anybody is looking to produce.