The notorious "in-law unit" is no longer just for the oldest share of adults in this country. Indeed, per the 2012 U.S. Census, 23.6 percent of young adults live in multi-generational housing, as compared to 22.7 percent of the oldest adults. According to Richard Fry and Jeffrey Passel of the Pew Research Center, this amount has steadily risen over the past three decades, "up from 18.7% in 2007 and 11% in 1980."
Fry and Passel explain that this trend might manifest from young adult's, "delayed entry into adulthood. Previous Pew Research Center studies have shown that young adults are marrying at later ages and staying in school longer." In addition,"the declining employment and wages of less-educated young adults may be undercutting their capacity to live independently of their parents."
Overall, an astounding, "57 million Americans, or 18.1% of the population of the United States, lived in multi-generational family households in 2012, double the number who lived in such households in 1980." This illustrates the shifting demand of the American population for housing stock that allows multi-generational living.