AT first glance, the prognosis for marriage looks grim. Between 1950 and 2011, according to calculations by the University of Maryland sociologist Philip Cohen, the marriage rate fell from 90 marriages a year per 1,000 unmarried women to just 31, a stunning 66 percent decline. If such a decline continued, there would be no women getting married by 2043!

But rumors of the death of marriage are greatly exaggerated. People are not giving up on marriage. They are simply waiting longer to tie the knot. Because the rate of marriage is calculated by the percentage of adult women (over 15) who get married each year, the marriage rate automatically falls as the average age of marriage goes up. In 1960, the majority of women were already married before they could legally have a glass of Champagne at their own wedding. A woman who was still unwed at 25 had some reason to fear that she would turn into what the Japanese call “Christmas cake,” left on the shelf.

Today the average age of first marriage is almost 27 for women and 29 for men, and the range of ages at first marriage is much more spread out. In 1960, Professor Cohen calculates, fewer than 8 percent of women and only 13 percent of men married for the first time at age 30 or older, compared with almost a third of all women and more than 40 percent of all men today. Most Americans still marry eventually, and they continue to hold marriage in high regard. Indeed, as a voluntary relationship between two individuals, marriage comes with higher expectations of fairness, fidelity and intimacy than ever.

But marriage is no longer the central institution that organizes people’s lives. Marriage is no longer the only place where people make major life transitions and decisions, enter into commitments or incur obligations. The rising age of marriage, combined with the increase in divorce and cohabitation since the 1960s, means that Americans spend a longer period of their adult lives outside marriage than ever before.