Will women marry down?

In a few weeks, the first of the 2011 college grads will toss their mortarboards in the air and bid adieu to campus life. A healthy majority of those hat-tossers — 57%, actually — will be women.

So here’s a question: when the time comes, will these women be willing to marry “down”? Don’t bet on it.

True, over the decades since women have been in the workforce, there has been a significant rise in the number of marriages where women bring home most of the bacon. As of 2007, 22% of wives were earning more than their husbands; that’s an impressive increase since 1970, when the number was only 4%. The percentage of couples where women have more schooling has also grown. Twenty-eight percent of wives have more education than their husbands; that is true of only 19% of husbands. The numbers were almost exactly the reverse in 1970, when 28% of husbands had more education, compared to 20% of wives.

But there are several reasons to believe that our new grads will not be growing these percentages by very much. For one thing, “breadwinner wives,” as women earning more than their husbands are sometimes called, are more common among couples where neither person has a college degree. For another, hypergamy, the term experts use for women marrying up, remains a powerful force in the mating market and explains many contemporary puzzles: Song-Yi and Woody Allen, Callista and Newt Gingrich, and Rula Jebreal and Julian Schnabel, not to mention Carrie and Mr. Big. Remember, 22% of wives may be earning more than their husbands, but 78% are not.

As for education, the most common practice is for like to marry like, or “homogamy.” According to research by Christina Schwartz and Robert Mare, homogamy has been going up, especially among the college educated. Not so long ago, highly educated women were a spinster class; men with degrees looked for wives whose talents ran towards cooking the dinner roast and doing the children’s laundry, not writing briefs. No longer. Women with advanced degrees are now as likely to marry as their less-educated sisters (though they are less likely to have children) in large part because educated men are choosing them over secretaries or nurses. Today about 55% of married couples have the same educational level. To coin a mouthful of a phrase, homogamy is replacing hypergamy.

It’s easy to figure out why educated men and women have finally found each other. For one thing, educated women now bring considerable income to the joint bank account. For another, Americans have grown to expect more equality and companionship in marriage than they did in the benighted past. It makes sense to assume that the University of Michigan grad will share interests and a mindset with someone he met in econ class rather than a clerk he locked eyes with at the DMV. This may be why, as several studies have found, husbands and wives with different education levels are more likely than homogamous couples to head to divorce court.