Back around Valentine's Day, I wrote a post about the ways in which it's cheaper to live as part of a couple. I noted that couples can also have some expenses that singles don't (gifts and "romantic dinners," for instance), but they pale in comparison to the cost of maintaining two separate households instead of one. Now, a recent article in the New Brunswick Star-Ledger speculates that this may actually be one reason why good old New Joysey has the lowest divorce rate in the nation: "because up here, well, it's just too expensive to break up."
There are other factors involved, of course. The article mentions several: couples in the Northeast are likely to wait longer to marry than Southerners, for instance, and they're more likely to live together before marriage (reducing the chances of a hasty decision). But the financial factor appears to be a significant one. One interviewee says the "half a house" he now rents in Somerville, NJ costs $500 more per month than the mortgage on his old house in Atlanta—meaning that the cost of maintaining two homes adds up to "thousands of dollars a month." The fact that average incomes are higher also adds up to "more money to fight about." A lawyer quoted in the article says that when she tells clients how much they're likely to end up paying in alimony, "their faces turn stone white and they look at me as if it's the second coming."
So I'd like to offer this addendum to my original post: while it may indeed be cheaper to live as a couple, getting married in order to save money is definitely not a good idea. Marrying in haste is a good recipe for a short marriage and an expensive divorce, and that's far costlier than staying single in the first place.