In a study that I conducted recently, I came across that the amount of children living with their grandparents and parents, which is what Demographers refer to as a family of three generations, has more than doubled over the last two decades.

Why is this happening? Is it a positive idea or a bad one?

The answer is complex. The reasons behind the trend can be as wide as social factors, ranging from the decline in the rate of marriage – and specific family situations, such as the loss of a parent’s position.

This is a trend worth studying as by better understanding the families children are living around, it is possible to develop better policies that are geared towards helping children. The programs that target kids tend to overlook those who live in the same household. If your grandmother is in the house, she’s important also.

A flexible unit for families

A three-generational household is one kind of living arrangement that is part of what Demographers refer to as”a “shared household” or a “doubled-up household.”

In a household that is shared, the child is living with at minimum one adult who isn’t a parent, sibling, or the parent’s spouse. This could be a cousin or aunt, uncle grandparent, or a family member.

In 2010, around one in five children lived in a family that was shared that’s an increase of 3 percentage points from 2007. In a study from 2014, I followed the same children over time and discovered that, by the age of 10, more than half of the children living in major U.S. cities lived in a household that shared an early point in their lives.

In order to further study, my colleague and I utilized two huge Census data set to analyze patterns based on the kind of living arrangements shared by the household.

We observed that, in general, the proportion of children living in households with shared families has increased since 1996.

However, the increase was almost all driven by an increase in one particular kind of family: Three-generation homes – often called multigenerational households that have children living in a home with a grandparent as well as either or both parents.

We also discovered that the percentage of children who live in a three-generation household has increased to 5.7 percent back in 1996 9.8 percent in 2016.

In other words, about 1 out of 10 of 7.1 million children live in a family with multiple generations. At birth, approximately fifteen percent of U.S. kids now live with their parents and grandparents, which is twice that of countries such as those of the U.K. and Australia.

There was also no change in percentage of children who live with their aunts and uncles and other relatives, or even non-relatives. We also did not find anything that suggested a growth within “grandfamilies,” also known as “skipped-generation households.” These are houses where grandparents are raising a grandchild with no parent living with them. Contrary to some reports in the media, the percentage of children who live in grandfamilies has remained at about two percent from 1996.

A pattern that has roots in more than just the recession

What is the reason for the increase in multigenerational households?

We discovered that the number of shared living arrangements increased during the recession, however it wasn’t solely due to the recession. Studies on the effects of unemployment throughout the Great Recession has found that the economic recession did not have a significant influence on the extent to which parents grew their family number of members.

In fact, the percentage of households with multiple generations was growing prior to even Great Recession – it actually began in the 1980s..

In addition, the number of co-living arrangements was increasing even as the economy grew.

This suggests that there are some other, deeper causes for the rise.

My research has identified three potential drivers.

The decline of marriage and an increase in the number of parents who are single means that more dads and moms live with their parents. They can assist with childcare as well as paying the bills.

Then, a larger percentage of U.S. children are non-white. Since families of minorities are more likely to have families and households, this shift in the population could be the reason for some of the rise.

Then we have the fact the majority of people getting Social Security. Since Social Security gives grandparents a regular source of income, It could be that grandparents are coming in to helping their children if their children’s earnings aren’t enough.