Does anyone stay together "'til death do us part" anymore?

London's Daily Mail reports [1] that co-habitating couples who never marry (think: Brad and Angelina) split up more frequently than married [2] couples. Granted, that might not be saying much considering the divorce [3] rate: in both the U.S. and the U.K., about half of marriages end in splitsville.

But apparently not slipping a ring around your finger when you share the same toothbrush holders means a breakup is all the more likely. Kids seem to complicate the problem—in the UK, half of co-habitating couples with a child break up before the kid's fifth birthday, versus one in twelve couples who are married with a kid. Could married couples be staying together for the sake of the kids? Could some couples just be more traditionally-minded than others?

Perhaps something about marriage isn't working for couples and the prevalence of unmarried couples and babies born out of wedlock [4] is being reflected in Britain's laws, granting them more legal protections a la divorce court. For examples, in the U.K., "common law" couples who own property in both their names are considered to own the property equally [5].

Perhaps Britain's unmarried couples are saying to themselves, "Why stay together if we're unhappy when our assets are legally protected, anyway?"