Commentators often remark on the relative decline of organized labor’s political clout over recent decades. Yet from recent big city mayor’s races such as those in Boston and New York to national campaigns to raise the minimum wage, labor unions continue to wield influence in certain circumstances. According to the nonpartisan Center for Responsive Politics, organized labor organizations donated approximately $76 million during the 2008 election cycle and more $141 million during the 2012 election, with more than 90% going to Democrats. However, while those numbers may seem large, labor’s political donations are now dwarfed by Republican-affiliated super PACs.

The massive decline in U.S. private sector labor union membership is strongly associated with general increases in wage inequality across society. In fact, research has found that between 1973 and 2007, the decline of unions explains one-third of the overall increase in U.S. wage inequality among men and one-fifth of the increased inequality among women. It has also produced greater “job polarization” within the labor market; some minority groups have felt these effects acutely. Union membership declines may have broader civic effects, too, but the precise dynamics have not been clear. Social scientists have become particularly interested in how decreased group affiliation and community attachment — crystallized by the scholar Robert Putnam’s “bowling alone” thesis — affects how Americans participate in public life.

Through formal training programs and informal means, unions seek to mobilize and guide political action among their members. Given the magnitude of these efforts, do they also cultivate broader social capital? A 2013 study in Social Forces, “Union Membership and Political Participation in the United States,” looks at the question. The scholars — Jasmine Kerrissey of University of Massachusetts, Amherst; and Evan Schofer of University of California, Irvine — based their work on three separate data sources on political behavior of American citizens from 1973 to 1994: The Roper Social and Political Trends Dataset, the American Citizen Participation Study, and the General Social Survey.

The study’s findings including:

• The effect of union membership on a range of political behavior was significant: Members were 18% more likely to vote in presidential elections than non-members, 43% more likely to volunteer for an election campaign, and 73% to 93% more likely to participate in protests.
• Union members are 13% to 20% more likely to join other voluntary associations, but they tend to be political in nature. In general, higher levels of political participation by union members did not carry over into broader civic engagement. For example, they were no more likely to donate money or carry out civic acts (such as blood donation) for programs or causes that were not related to their union or its political agenda.
• The impact of unions was greatest for those with low levels of education. For example, “the predicted probability of having participated in a protest is around 0.04 for a union member with no formal education, which is five times higher than the estimated 0.008 probability for a nonmember. Among those with a high school degree, the probabilities are about 0.10 for union members versus 0.05 for nonmembers, still a sizable gap.”
• While the study found that the impact of union membership on low-income members was too small to constitute a significant difference, other studies have identified substantial effects: A 2010 study from Notre Dame University and Texas A&M University found that membership increased life satisfaction for workers earning below-average incomes compared to those earning higher incomes. “It is the most vulnerable members of society who are most positively affected by membership and the influence of organized labor in the industrial world,” the authors concluded.
• Unions were more likely to have political issues on their meeting agendas than other organizations: 75% of union members reported that political issues were on meeting agendas, compared to 56% for members of neighborhood organizations and 31% for members of religious organizations.
• The probability was greater of unions taking stands on political issues: 72% of union members reported that their organization did so, compared to 53% for neighborhood organizations and 32% for religious organizations.
• “Unions are very explicit in their efforts to cultivate political participation among the working class and those that lack civic skills. It appears that those efforts are remarkably successful, given the large participation effects that we observe,” the researchers write.
• The long-term decline of unions — U.S. membership peaked 34% of the workforce in 1955, and was 12.4% in 2008 — could have significant negative impact on political participation. “Union decline … has implications for the composition of public life, shrinking the voice of those with less education. Unions are powerful engines of political participation, and their decline betokens a less democratic future for American politics.”

Overall, “it appears that unions build ‘political capital’ more than generalized ‘social capital,'” the authors conclude. Union membership does increase the probability of joining other voluntary associations, but these are often political in nature. “These patterns are broadly consistent with our structural arguments: American labor unions face strong pressures to mobilize members to prepare for collective action with employers and to maintain political capital with the Democratic Party.”

Keywords: labor unions, political participation, organized labor, social capital