Sometime while Hillary Clinton was switching her name from Hillary Rodham to Hillary Clinton and back again and back again, an important threshold was crossed – people stopped caring. When Hillary initially kept her surname after marrying Bill, it was a blow against the patriarchy and for women’s liberation, but today such surname-keeping has lost its cachet.

In the 1990s the number of women keeping their maiden name upon marriage began to dip, according to a fascinating study published in The Journal of Economic Perspectives. This snapback to taking a husband’s surname is mostly an elite phenomenon, since among most people it never went out of style. Roughly 90 percent of women take their husband’s surname. It is among college-educated women that surname-keeping flowed and is now ebbing.

Surname-keeping took hold in the 1970s. Legal restrictions that forced women to take their husbands’ surnames began to be overturned or ignored. Women began to marry later and get more professional degrees, both of which made them more attached to their surnames. Ms. became popularized as a way to avoid the repression of Mrs. Keeping a surname was considered a way for a woman to keep her identity.

The number of women in The New York Times’ wedding announcements keeping their surnames was 2 percent in 1975 and had reached 20 percent by the mid-1980s, according to the Journal study. Then the trend stalled. Among women in the Harvard class of 1980, 44 percent retained their surname, but in the class of 1990, only 32 percent did. According to Massachusetts records, the percentage of surname-keepers among college graduates in that state was 23 percent in 1990, 20 percent in 1995 and 17 percent in 2000.

Why? The study’s authors write: “Perhaps some women who kept’ their surnames in the 1980s, during the rapid increase in keeping,’ did so because of peer pressure, and their counterparts today are freer to make their own choices. Perhaps surname-keeping seems less salient as a way of publicly supporting equality for women than it did in the late 1970s and 1980s. Perhaps a general drift to more conservative social values has made surname-keeping less attractive.”

Indeed, the decline in surname-keeping might mean that marriage is being taken slightly more seriously. “I think it will strengthen marriage,” says University of Virginia professor Steven Rhoads, author of “Taking Sex Differences Seriously.” “It’s a sign that someone intends it to be a unit, that this is a marriage, and it is for the duration.”

It certainly shows that, for whatever reason, younger women are moving beyond old feminist obsessions. Writing in the online magazine Slate, Katie Roiphe argues that “the maiden name is no longer a fraught political issue. These days, no one is shocked when an independent-minded woman takes her husband’s name, any more than one is shocked when she announces that she is staying at home with her kids.”

In the waning of a certain kind of self-conscious feminism, women are freer to make their own choices – including traditional ones.

Finally, there is simply the hassle factor. It can be difficult for a mother who doesn’t share her child’s last name to pick him up from school or travel with him. Hyphenation has its own perils. Writer Frederica Mathewes-Green reports receiving mail for people named Mathwas-Green, Mathers-Crein, Vatherwes-Green and Mebhews-Creen, among others. Her hyphenation won’t be carried on by any of her children, and she doesn’t regret it.

In an essay on the decline of feminism in the City Journal, Kay Hymowitz notes that feminist pioneer Patricia Ireland recently wrote that a woman taking her husband’s name “signifies the loss of her very existence as a person under the law.” Women who want to get on with their lives and with their marriages greet that kind of old-school feminist call-to-arms with a decidedly 21st century “ho-hum.”

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.