Robert D. Putnam, a Harvard social scientist that famously authored Bowling Alone, recently ignited a national conversation about upward mobility with a new book titled Our Kids. He persuasively argues that growing inequality in income and wealth is leading to profound social changes that make it increasingly harder for children from low-income families to get ahead. What we found out this week at the Center of the American Progress (CAP) is an important contribution to this debate.

Researchers at Harvard, Wellesley, and the CAP paired up to study the effects of union membership on social mobility. Although it is well established that unions raise wages for their members, little was known about their impact on economic opportunity for the disadvantaged. To explore this relationship, they looked at aggregate data at the city level and a second data set that pairs individuals with their parents.

Their findings should come as no surprise to those of us who witness how unions lift up our communities: there is a strong relationship between union membership and intergenerational mobility. In other words, unions help low-income children move up the economic ladder. The effect is constant even as you control for other factors such as race, types of industry, and inequality. Moreover, the individual-level data reveals that children who grow up in union homes tend to have better outcomes. For instance, children of non-college-educated fathers earn 28 percent more if their father belonged to a union.

The most fascinating aspect of the study relates to the work that we do in Bargaining for the Common Good. While we anticipate that unionized parents who make more will transfer higher wages to their sons and daughters, the researchers also found that higher union membership leads to greater mobility for all children – even those whose parents are not union members. The authors posit that the reason this happens is that organized labor advocates for policies that benefit all working people—like minimum wage increases, public education, and city services. These are precisely the types of policies that unions and their community allies have promoted in Los Angeles, Chicago, St. Paul, and across the country as they apply the Bargaining for the Common Good philosophy to their contract negotiations with local government.

It is no wonder that Americans view unions more favorably. Even critics of labor are changing their minds. By prioritizing bargaining demands that improve society as a whole, unions are helping ensure that our kids have the capacity to succeed regardless of their family’s income.