According to the US Census Bureau, there were 500,000 couples living together in 1970; now there are more than 3.7 million. Slightly more than half of adults in their 20s and 30s have lived with a squeeze. Why such a dramatic rise? Factors may include: economic necessity, relaxation of taboos, increased desire to freak out parents.

But more important than the question of why couples love-shack is this: what happens when they do?

Two recent studies offer some concrete answers.

1. A Penn State study found that cohabiters are less enthusiastic about marriage than those who live with their parents. Now, before you say, “Duh, I’d marry The Grinch to get out of living at home!” allow me to finesse this finding. Point is: living together actually caused couples to get less psyched about getting married. Now, before you say, “Duh, ’cause they realize they’d be marrying the Grinch!”let me further finesse. They don’t get less psyched about each other; they get less psyched about marrying each other — and more psyched about keeping things the way they are.

2. Just last month, a Bowling Green (Ohio) State University study presented to the American Sociological Association found that in some cases, moving in can get you down. Of the couples studied, the measure of “life satisfaction” was highest for married couples and next-highest for couples who lived together two years or less (that is, until marriage or breakup). Whose “life satisfaction” was at rock bottom? Long-term live-ins . Huh. And notably, cohabiting women with kids were significantly more depressed than married mothers. Sociologist Susan Brown surmises that what’s behind these blues is the wear and tear of, if you will, the relationship’s permanent impermanence.

Now that I reread them, I see that putting these studies together in close quarters underscores their trivial differences. Funny, that. But anyway, what we can distill from both of them — and from pretty common credence — is this: living together does not necessarily work as a dress rehearsal for marriage. How come? Well, for one thing, you’ve said “I do” only to the landlord, not to each other; there’s always – in theory –– a relatively easy out (unless you live in Manhattan, where the only way to get a good place is to marry a landlord). It’s NOT the same.

But I’m not telling you not to live together, I’m just telling you not to do it as a dry-run. Do it because you can’t stand to go one minute in the morning without seeing each other. Do it because you’re totally committed to each other and aren’t interested in the institution of marriage. Do it because your housemates have already turned your room into a study, anyway. Okay?

Other than that, BG does not have a particular pro or con position on living together — she prefers to evaluate your lovenests on a place-to-place basis. Just a couple more things to note, though, as you load up the U-Haul of love: (1) your cohabitation will make it approximately 89% more difficult for your friends to find worthwhile wedding presents, and (2) make no mistake: even if you live in the same room, you will still email each other. Oh, and if you’re looking for someone to live with, consider attending the next social at the Brotherhood of Carpenters and Joiners. They sound rather handy.

A version of this column was originally published on September 7, 1998.