Well, my wife is killing me with "communication". If she came home and there was another women there she could "communicate" with and I did not have to absorb her stress or get in trouble by trying to fix her problems... I am sure I'd be healthier and live longer.
A little competition for my affection, without having to bring in a woman outside the marriage, would probably do wonders for me as well!
I'd like to know if the wives in a multiple-wife marriage live longer as well. Maybe this is a win-win (win-win-win).
Or course the unspoken fear is that if married to two wives there would still be no sex (with me, anyway).