Three Generations, One Roof

University of Michigan Professor Natasha Pilkauskas finds one type of household is on the rise
Natasha Pilkauskas // Photograph Courtesy of Natasha Pilkauskas


So, it seems the nuclear family — one that is comprised of a mother, father, and two children living together under one roof — is beginning to dismantle. In the United States in 1970, 40 percent of households were nuclear. Today, that number is less than 20 percent. Professor Natasha Pilkauskas, an assistant professor of public policy at the University of Michigan, says what has taken its place is the three-generation family.

Pilkauskas defines this as the type of family where three generations reside simultaneously — child, parent, and grandparent. Between 1996 and 2016, she calculated a rise of more than 4 percent in this category of living arrangement. That means that today, there are roughly 1 in 10 children living with at least one parent and one grandparent, a rate that’s double that of places like Australia and the U.K.

Pilkauskas, whose previous research centered specifically on children living in low-income three-generation households, has now made a career out of studying the living structure. Her initial notion was to see which types of households had increased over time. “I was surprised to see that only this one had, at all income levels,” she says.

While the exact reasons for this rise remain ambiguous, Pilkauskas points to a number of wide-ranging social trends to provide context.

The first is the decline in marriage. Reports from Pew Research Center show that the percentage of married adults has dropped from 72 percent in 1960 to roughly 50 percent in 2016.

The second is the increase in single parenthood. According to Sara McLanahan, professor of sociology at Princeton University, and Christopher Jencks, professor at the Harvard Kennedy School, the percentage of children living with unmarried mothers — across all races — has increased from less than 10 percent in 1950 to nearly 25 percent by 2010.

Pilkauskas suggests that maybe more young parents are moving in with their parents for childcare and financial assistance. “Single parenthood is a significant factor in explaining the increase of three-generation families. It accounts for about half a percentage point.”

The final trend she notes is the growing share of the American population that identifies as non-white. Population predictions from the 2018 U.S. Census project that the country will become minority white, about 50 percent of the population, by 2045. “Every group besides white folks has much higher rates of co-residence,” she says, “perhaps it’s either culturally relative or culturally normative.”

There are roughly 1 in 10 children living with at least one parent and one grandparent, a rate that’s double that of Australia and the U.K.

Pilkauskas has observed that three-generation living structures have positive associations for black and Hispanic children, and more negative associations for white and Asian kids. “That’s regardless of income, but also making mass generalizations,” she says. “What I can see is that that the grandparents in white and Asian households are older on average than that of black and Hispanic households.”

Based on this research, Pilkauskas has charted a few courses for further study. One is looking at how this trend has evolved over history starting in 1870. Another is analyzing the three-generation family through the lens of Social Security.

“We’ve found that Social Security was one of the drivers of this change and that was really surprising to me.” Perhaps the reasoning is that Social Security offers grandparents a steady source of income and allows them to help out their grandchildren when their own children’s incomes are insufficient. “Historically, Social Security meant people could live independently so it’s a surprise that it’s partly what’s explaining the increase,” she says.

Pilkauskas’ work may serve as the foundation for future policy changes.

Innovate is an ongoing series that spotlights local thought leaders and the studies, innovations, and ideas they are generating across metro Detroit.