One of the more striking and underappreciated social and economic trends in recent decades has been the shift toward multigenerational living. One in four Americans live in a household with three or more generations under one roof, according to a recent research report by Amy Goyer for the nonprofit Generations United. The number has nearly quadrupled in the past decade.

The pandemic accelerated the trend. Millions of young adults moved back home during COVID-19. Scared by the high death toll and lockdown loneliness in assisted living centers and similar institutions, some families opened their homes to aging parents and relatives. Some of these newly formed multigenerational households will break up as the economy opens up and the coronavirus threat recedes. But far from all.

For one thing, the demographics of a changing America has profoundly shaped the change in living arrangements. For another, the economics of multigenerational living are compelling.

Pooling financial resources among the generations is a smart way to lower the overall cost of home ownership. Shared living allows young adults to build up savings and the older generation to draw down less on their retirement savings. That's before considering built-in childcare and easy monitoring when aging parents turn frail.

Multigenerational living isn't for everyone. Not all families and extended families get along. Even among generations who like each other, there is a need establish boundaries, respect privacy and allow for independence.

Near retirees and early retires should investigate the practicality of setting up a multigenerational home. The National Association of Realtors has observed that buyers who bought homes since March 2020 were more likely to buy a multigenerational home than in the months before the pandemic. Living under one roof is only one possibility, too. Other options include garage apartments and other "accessory dwelling units." Families may also move into the same neighborhood to be close.

Whatever the details of living together or in close proximity, the arrangement looks like a winning combination. "Multigenerational households draw upon the strengths of multiple generations, working together to create solutions in the best interest of family members across a range of generations," concludes the Generations United report. "The result is resilient families who get through both good times and challenging times together, and the outcome is a stronger, more caring nations."

Chris Farrell is senior economics contributor to "Marketplace" and Minnesota Public Radio.