The Downside of Cohabiting Before Marriage - NYTimes.com
It is still true that cohabiting couples are more likely to divorce. I have always maintained that women agree to move in with a man hoping it will lead to marriage, while men want to cohabit because it means they won't have to get married. It's the old saying, "Why buy a cow when milk is so cheap?" And the Times author puts it this way:
... partners often have different, unspoken — even unconscious — agendas. Women are more likely to view cohabitation as a step toward marriage, while men are more likely to see it as a way to test a relationship or postpone commitment, and this gender asymmetry is associated with negative interactions and lower levels of commitment even after the relationship progresses to marriage. One thing men and women do agree on, however, is that their standards for a live-in partner are lower than they are for a spouse.Read the whole thing.