IMO marriage has been marginalized by today's shack up culture and people don't see it as a valued commitment that requires attention and integrity to the principle by both people. Its become more of a value as a means to an end, in its end, by many. Surprisingly the divorce rate has gone down recently. I remember hearing the study, but not what was or what was not factored into it, but at first glance I would say that many of those people who don't value marriage are simply not getting married, deciding to go with the co-existence theory subject only to palimony. I could of course be incredibly wrong, but its my shot in the dark at an explanation for divorces decline.