Economist Nicholas Eberstadt lays out a bleak future in an important essay just published in The Wall Street Journal. Eberstadt makes the case that selfishness, as evidenced by the unwillingness of people to get married in the first place and stay married in the second, is setting humanity on an unknown and potentially dangerous course.

Eberstadt describes a global flight from family. “All around the world today, pre-existing family patterns are being upended by a revolutionary new force: the seemingly unstoppable quest for convenience by adults demanding ever-greater autonomy,” he writes.

“Thanks to this revolution, it is perhaps easier than ever before to free oneself from the burdens that would otherwise be imposed by spouses, children, relatives or significant others with whom one shares a hearth,” he continues.

What Eberstadt shows is not just the ever-expanding incidence of fatherless homes, which is old news by now, but the breakdown of family in ever new ways and directions.

In the United States, “a 2011 study by two Census researchers reckoned that just 59% of all American children … lived with married and biological parents.” Eberstadt says that in the foreseeable future, “American children who reside with their married birthparents will be in the minority.”

What may shock many is the exploding number of men and women who are simply not interested in marriage–ever. Eberstadt cites data from Belgium where “the likelihood of a first marriage for a woman of reproductive age is now down to 40%, and the likelihood of divorce is over 50%.”

Eberstadt says Europe is seeing a “surge in ‘child-free’ adults–voluntary childlessness.” One in five 40-something women in Sweden and Switzerland are childless. That number is one in four in Italy, and one in three in the German city of Hamburg. In fact, Eberstadt says, “Europe’s most rapidly growing family type is the one-person household.” In Western Europe, one in three homes are already “a one person unit.”

And this is not just a Western phenomenon. Asia is following suit. One-sixth of Japanese women in their 40s are still single, and “30% of all women are childless.” The same trends are happening in South Korea, Singapore, Taiwan, and Hong Kong.

Lest anyone think the world is about to be overtaken by a wash of Muslim births, not only is the Muslim birth rate plummeting all over the Middle East, Muslims are also walking away from marriage. Eberstadt cites UN data that show that “the proportion of never-married women in their late 30s was higher in Morocco in 2004 than in the U.S. in 2009 (17% vs. 16%). And nearly 32% of Libyan women in their late 30s were unmarried in 2006.”

The Europeans have called this the Second Demographic Transition, the first being the period in the 1800s in Europe when high birth rates began to decline, as did death rates, a phenomenon that is now nearly universal and has resulted in rapidly aging populations.

The Second Demographic Transition portends great difficulties for societies and governments and specifically for those Eberstadt calls “the most vulnerable,” the young and the old. He says, “The deleterious impact on the hardly inconsequential number of children disadvantaged by the flight from family is already plain enough.”

The same flight from family “also has unforgiving implications for the vulnerable old.” A “gray wave” is about to hit societies because of the retirement and aging of the Baby Boom. “In the decades ahead, ever more care and support for seniors will be required, especially for the growing contingent among the elderly who will be victims of dementia, or are childless and socially isolated.”

Eberstadt concludes, “It is far from clear that humanity is prepared to cope with the consequences of its impending family deficit, with increasing independence for those traditionally most dependent on others–i.e., the young and old.” He points out that “government is a highly imperfect substitute for family–and a very expensive one.”