Who’s Putting a Roof Over Parents’ Heads

Do you really need that in-law suite?

That depends chiefly on where your in-laws were born. A new study by Jed Kolko, the chief economist at Trulia, the real estate Web site, finds that the chances of your children’s having live-in grandparents are greater if those grandparents are from India, Vietnam or Haiti. In fact, foreign-born adults are four times more likely than natives to live with relatives, Mr. Kolko found.

Over all, about 9 percent of older Americans live with relatives, according to Census data. But close to half of those born in India (47 percent) and Vietnam (44 percent) live with family members, while those born in Germany (6 percent) and Canada (5 percent) are slightly less likely than American-born seniors to live with relatives. (Trulia has published a full list of countries.) Among the American-born, those of Hispanic or Asian descent are the most likely to live with relatives when they grow old.

Women, the unmarried, and the “old old” â€" 85 and older â€" are also more likely to move in with their children.

In recent years, the share of older adults living with their children or other relatives has increased, to 7.3 percent in 2013 from an average of 6.6 percent from 1994 to 1998. But unlike those basement-dwelling millennials who are still living with their parents, older Americans who do so have not been motivated by financial reasons, Mr. Kolko says. The trend has been long-term, in keeping with immigration patterns rather than driven by the recession. And local housing prices were not a determining factor.

But the percentage of older residents in the area was important â€" the younger the city’s population, the less likely for the aging to live on their own. Mr. Kolko found wide variation: In Miami, more than 1 in 4 are living with relatives, and heavily Hispanic cities like Los Angeles, El Paso and New York also rank high in the share of seniors in multigenerational households. Omaha, Toledo and Minneapolis rank the lowest.