Good article in the NY Times on the growth of multifamily households. Called "doubling up" in the social service world, the recession has caused a large increase in the number of households with multiple families.
Key quote from the article:
Census Bureau data released in September showed that the number of multifamily households jumped 11.7 percent from 2008 to 2010, reaching 15.5 million, or 13.2 percent of all households. It is the highest proportion since at least 1968, accounting for 54 million people.
The numbers are actually higher. The Census does not include siblings living together or when a childless adult lives with his or her parents, or a parent/parents lives with adult children.
While the recession amplified the impact of this trend, doubling up started becoming more common in the in 1990s. A combination of higher costs of living, the need to care for aging parents and 2 income families looking for childcare assistance resulted in the formation of more multifamily and multi-generational households.
The growth of multifamily and multi-generational households is one component of the broader new localism trend.