SOMETIME while Hillary Clinton was switching her name from Hillary Rodham to Hillary Clinton and back again and back 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...