Census data shows that the fastest-growing household type in the U.S. is the "multigenerational household," one that includes members of three generations or more.

It's not exactly a new idea -- and while in this individualistic age it may be the disadvantages that leap to mind first (Who wants to hear, "You're going outside in that?" at the age of 35 or so?), it doesn't take much deep thinking to see the advantages, particularly for children, too often deprived of close relationships with their grandparents, and for young parents starting out, for whom housing and child care costs are a major burden.

According to a NY Times article, some of the growth is culturally driven, as immigrants from countries where the multi-generational model is the norm (as it was in this country until the advent of Social Security made independent living affordable for more elderly Americans) carry on that tradition. Single parenthood is another contributor, with young mothers often relying on their own mothers and fathers for financial and child-care support. Most multi-generational households are low or moderate income, and clearly the financial advantages are important.

But another segment of the growth seems to be driven simply by preference. Developers are catching on, building houses and planning developments geared at a new niche market of well-off multi-generational households.

When my children were small, we lived for two years in the Republic of Macedonia, a country where the multi-generation model was the norm. Though Macedonia struggles with serious ethnic divisions between Slavs, ethnic Albanians, Roma and Turks, all the groups at least have that in common. Grandmothers -- babas -- ruled the roost in the neighborhoods, caring for young children while their parents were at work, sweeping the sidewalks outside their homes and keeping an eye on older children at play. It made for a neighborhood setting so safe that my three-year-old son could walk out the door to play with neighborhood children -- a very unsettling luxury for me.

There was a whole different ethic of care among the children, as well, with older children keeping a big-sibling eye on all the younger kids, whether related or not. In fact, most of them were related, at least as cousins, since each neighborhood tended to be settled by people from a particular village. But the babas were the glue that held it all together.

Still, there was a feeling of change in the air. Some of the younger women -- the mothers -- told me that they felt this arrangement was not modern. And a primary school teacher complained to me once that children who stayed at home with their babas rather than attending preschool entered first grade unprepared -- "They can't tie their shoes, they can't button their coats, they can't do the simplest things!"

Here in the U.S., multigenerational households were still only 4 percent of all households in 2000 -- but that was a 38 percent increase from 1990, and real-estate and building industry sources say the trend has accelerated since then. It will be interesting to see how far back this particular pendulum will swing.