http://globaleconomicanalysis.blogspot.com/2012/10/multigene...

Multigenerational Households On Rise

More than 4.3 million, or 5.6 percent, of the 76 million family households in the U.S. today are multigenerational households, or families living together that include a grandparent, parent and children as well as other family members, according to a study by the U.S. Census Bureau's American Community Survey.

3.7% in 2000
4.0% in 2010
5.6% in 2012


If the trend continues--it will drive apartment rents down & negatively effect apartment REIT returns.