Married couples represented just 48 percent of American households in 2010, according to data being made public Thursday and analyzed by the Brookings Institution. This was slightly less than in 2000, but far below the 78 percent of households occupied by married couples in 1950.
What is more, just a fifth of households were traditional families — married couples with children — down from about a quarter a decade ago, and from 43 percent in 1950, as the iconic image of the American family continues to break apart.
The biggest change for the decade was the jump in households headed by women without husbands — up by 18 percent in the decade. The next largest rise was in households whose occupants were not a family — up by about 16 percent, Mr. Frey said.
Households are changing in other ways. Americans are living longer than ever, so households now include a growing number of elderly singles, said Andrew J. Cherlin, a demographer at Johns Hopkins University. Other factors have been the large influx of immigrants, who tend to be single people in their 20s and 30s, and the growing number of young people who live together without being married.