The NYT has an article about marriage falling out of the majority but they don't mention that even though less than half of households include a married couple, the majority of people still live in such households.
The numbers by no means suggests marriage is dead or necessarily that a tipping point has been reached. The total number of married couples is higher than ever, and most Americans eventually marry. But marriage has been facing more competition. A growing number of adults are spending more of their lives single or living unmarried with partners, and the potential social and economic implications are profound.“It just changes the social weight of marriage in the economy, in the work force, in sales of homes and rentals, and who manufacturers advertise to,” said Stephanie Coontz, director of public education for the Council on Contemporary Families, a nonprofit research group. “It certainly challenges the way we set up our work policies.”
While the number of single young adults and elderly widows are both growing, Professor Coontz said, “we have an anachronistic view as to what extent you can use marriage to organize the distribution and redistribution of benefits.”
A household with a married couple obviously includes at least twice as many people as a household consisting of a single adult. Although the exact percentage of single member households isn't given, we can determine it from the article.
The American Community Survey, released this month by the Census Bureau, found that 49.7 percent, or 55.2 million, of the nation’s 111.1 million households in 2005 were made up of married couples — with and without children — just shy of a majority and down from more than 52 percent five years earlier. ...The census survey estimated that 5.2 million couples, a little more than 5 percent of households, were unmarried opposite-sex partners. An additional 413,000 households were male couples, and 363,000 were female couples. In all, nearly one in 10 couples were unmarried. (One in 20 households consisted of people living alone).
No other percentages are included, but by those numbers it appears that about 45% of households consist of single adults (with or without children), meaning that it's likely that those in the married households still greatly outnumber everyone else.
In all though, I think the evidence in the article demonstrates that marriage is not as important an institution for survival as it once was. Our country has become so prosperous that many people don't find it necessary to have a family to succeed and discover that they can do just fine on their own. That speaks well of our economy, but I hope that such easy survival doesn't lead to decadence and the breakdown of the culture that made our prosperity possible.