Informed Preferences: the Impact of Unions on Worker’s Policy Views

The following is part of a series of posts written by 2016 MPSA award recipients highlighting outstanding research presented at previous MPSA annual conferences.

What is the impact of labor unions in shaping the political preferences of workers? More specifically, to what extent can we trace the anti-trade sentiment we are now seeing among many U.S. workers to the influence of their unions? Due to their shrinking memberships, unions are often dismissed as a spent force in contemporary politics. Yet such a view overlooks an important point: Even after years of membership decline, unions still represent a sizable share of many electorates: a quarter of all workers in Britain, a third in Italy, and over half the workforce in countries such as Norway or Belgium. Even in the U.S., union members still account for about 11 percent of the workforce—a conservative figure that excludes non-members working under union agreements and family members whose livelihoods often depend on a unionized wage earner. A key question is whether and how unions’ access to a large swath of the electorate translates into political influence.

To understand the role that unions play in shaping the political views of their members is, however, a challenging empirical task.  Even in instances where union members are found to hold systematically distinct views from non-members, the cause is not an obvious one: Is it the result of a union’s direct influence on workers’ policy views, or is it that workers who choose to join a union differ from non-members to begin with?

Our article seeks to provide answers to these questions by utilizing an original survey of more than 4,000 American workers that was administered across 12 industries selected to provide the full range of exposure to various aspects of globalization. The dataset provides sizable samples of both union members and non-members within each industry, allowing for comparisons with a meaningful control group. Another key advantage is the availability of detailed information on pertinent aspects that are often missing from standard surveys: the exact union to which the worker belongs, the intensity of communication initiated by their unions on a range of policy issues, and the degree to which a worker is aware of her union’s policy positions. To assess how accurately workers know their union’s position, we devise a new measure of a union’s position on trade policy (what we call the “protectionism score”). This measure is based on a union’s ‘revealed preference’, namely through their lobbying activity and official statements given on a wide range of trade bills.

Using this data, we begin to explore whether unions indeed serve as information providers for their members. The evidence decidedly shows that they are. (See Figure 1;  unions are sorted along the vertical axis by their protectionism score.) As the left-panel indicates, unions indeed discuss the issue of trade with their members, and, not surprisingly, the more protectionist the union, the more likely it is to impart such information to their members. We can also see that the intensity of the communication is associated with how familiar members are with their union’s position (center panel). Members of protectionist unions not only tend to express greater familiarity with their union’s stance on trade, but also to correctly describe their union as protectionist (right panel).


Figure 1


In short, unions clearly operate as information providers. Moreover, workers also seem to ‘get’ their union’s message. Yet to what extent do members tend to be influenced by this message and adopt their union’s position? As an initial step, we examine the association between members’ own attitudes on trade and the protectionism score of their unions. We find a clear alignment between the two. Notably, such positive association is not found among non-unionized workers who are employed in the same industry (see Figure 2). Still, the key empirical task here is to assess the possibility of a self-selection process: If workers decide to join a union because of the union’s policy position, the findings could simply be an outcome of a reverse causal process. We address this possibility by exploiting two sources of variation, as detailed below.

Figure 2


First, we leverage the fact that there are state-level differences in laws with respect to union membership, or so-called the “Right-to-Work” (RTW) laws. In states that adopt the RTW provision, labor unions cannot legally require workers to pay union dues as a condition for employment. Union membership in RTW states therefore depends much more on individual workers’ own discretion, and is less a function of an institutional requirement to become members. This difference allows us to test the self-selection question: If self-selection accounts for members’ preferences, we should expect to see unions have much more of an influence on members in states in which membership is entirely voluntary.

Our analysis provides very little support for the self-selection account. We find that union membership itself is associated with a clear effect on the trade policy views of workers, and that this effect is conditional on how strong the union’s position is with respect to trade. Significantly, we find no systematic difference between members in RTW and non-RTW states. This is clearly inconsistent with the selection mechanism being the prominent factor.

Second, we wanted to assess what happens to the views of members when their union takes a different stance on a given policy: do workers follow suit? If so, that would be a strong indication of the unions’ influence. To do so, we exploit the case of a sudden and dramatic shift in the United Auto Workers’ (UAW) position toward a major trade liberalization deal. For many years, the UAW had been strongly opposed to the signing of a trade agreement with Korea, which, according to its statement, would be “worsening our lopsided auto trade deficit and threatening jobs of tens of thousands of American workers.” Yet after a set of changes had been incorporated into the agreement, the UAW announced a reversal of its position. “We believe an agreement was achieved that will protect current American auto jobs, [and] that will grow more American auto jobs,” its statement now read.

How did this shift in the UAW’s position influence the views of the autoworkers on trade? Figure 3 below provides a striking answer: While union members working in the auto industry had been significantly more protectionist than non-members before the shift, the level of support for trade restrictions significantly decreased after the UAW endorsed the free trade agreement. Notably, this change in attitudes toward trade liberalization had not been observed among non-members working in the same auto industry. This finding remains intact even when we control for potential confounding factors.


Figure 3

Taken together, our findings provide compelling evidence that unions exert influence on their members in a clear and systematic manner. The analysis points to the important role of unions as information providers. While previous studies have highlighted the role of unions as the “voice of workers,” via campaign contributions or lobbying, we have demonstrated an underexplored yet important source of union influence: communication with, and dissemination of information to members. This influence can be significant, given unions’ breadth and reach. In other words, unions should be thought of not only as institutions that channel the political preferences of their members. Instead, they should also be understood as institutions that shape and influence the views of many workers.


MPSA_Awards_RecognizingOutstandingResearchAbout the Authors: Sung Eun Kim is an Assistant Professor of Political Science at the National University of Singapore.  Prof. Yotam Margalit is an Associate Professor at the Political Science Department in Tel-Aviv University. He is also a Senior Fellow at the Israel Democracy Institute. Their paper “Informed Preferences: the Impact of Unions on Worker’s Policy Views” was awarded the Best Paper by an Emerging Scholar at the 2016 MPSA Conference.