My position is that polygamy should be tolerated, but not celebrated (or recognized by law). My reasons:
1) It will probably lead to a shortage of women, as some men hog all the women for themselves. Women are more willing to share a man than vice-versa. (Whether this is cultural or biological is irrelevant. Either way you'll end up with a shortage of women.)
2) Poly marriages are not as stable as two person relationships. The more premises an argument has, the less likely it is to be sound; so too for marriage. Dan Savage says that he's been to number of "poly weddings", but has never been to a poly tenth anniversary party.
Women are more willing to share a man than vice-versa.
This may be a dumb question on my part, but is this from personal observation, studies you know of, other?
ie, I know there're places where one man is allowed to marry multiple women, but not other way around, for example... But do we have reason to think that if suddenly we went "poof, now it's allowed both ways" in a western society that, until then, was mostly monogamous, it'd default to "few/single men, many women" type marriages?
(Just to clarify, I'm not arguing against you so...
A thought occurred to me today as I skimmed an article in a rationality forum where the subject of gay marriage cropped up; seeing as the issue has been hotly contested in various public fora and especially the courts, what about poly? After all, many if not all the arguments for gay marriage apply to poly marriage as well.
Questions for LWers who are currently in a such a relationship, or have an opinion to share:
Do polies want to marry each other or do such relationships not lend themselves to permanence above a threshold of partners? Should polies campaign for the right for a civil union anyway? what are the up and down sides of this? etc