Wait, if polygamy was legalised would there be more tax benefits for having two spouses than if you had one? And would it accumulate? And couldn't in theory there be a commune of enough spouses that the simple influx of benefits and tax breaks would break the government? Cool.
Personally, I like the idea of polygamy, but I've never found any woman who was as good at sharing as is necessary for the arrangement. If its coercive or if its a man with a wife in every port so to speak, then its just dangerous.
So all in all I vote for multiple spouses and bigger tax breaks.
I wouldn't have a problem with a polygamist relationship, though I doubt my girlfriend is up for sharing, so I think its a right off anyways.