A Switch or a Process? Disentangling the Effects of Union Membership on Political Attitudes in Switzerland and the UK

• Author: Sinisa Hadziabdic,Lucio Baccaro
• Date: 01 July 2020
• Published date: 01 July 2020
• DOI: http://doi.org/10.1111/irel.12264

A Switch or a Process? Disentangling the Effects

of Union Membership on Political Attitudes in

Switzerland and the UK

SINISA HADZIABDIC

†

and LUCIO BACCARO

The paper examines the effects of union membership on individual political atti-

tudes using panel data for Swiss and British workers. Considering union member-

ship as an on/off switch (member vs. non-member), as it is often done, it is only

possible to distinguish between a selection effect (unions attract like-minded indi-

viduals) and a molding effect (the experience of membership has a transforma-

tional impact on the individual). Exploiting the longitudinal structure of the data

reveals that union membership is best characterized not as a switch, but as a

dynamic process involving anticipation effects (which start well before becoming

affiliated) and maturation effects (which become noticeable only after a certain

duration of membership and may not dissipate after leaving the union). Empiri-

cally, the selection effect appears the most important in the two countries we

focus on, while the molding effect is less pronounced. Anticipation and matura-

tion effects are also non-negligible and hitherto unexplored.

Introduction

A time-old literature argues that membership in labor unions increases the

individual propensity to be politically involved, participate in elections, and

vote for pro-labor parties. An even broader social science literature maintains

that associational membership in general, including union membership, has a

transformative effect on participating individuals. In reality, the empirical vali-

dation of these plausible claims is less straightforward than most literature

assumes. In particular, as we discuss in this article, the modal type of analysis

—based on cross-sectional data and lacking a longitudinal dimension—

†

The authors’affiliation is Max Planck Institute for the Study of Societies (MPIfG), Cologne, Germany.

E-mail: hs@mpifg.de.

We thank Jonas Pontusson, Pascal Sciarini, and Michele Pellizzari for helpful comments on an early draft of

this paper.

INDUSTRIAL RELATIONS, DOI: 10.1111/irel.12264. Vol. 59, No. 3 (July 2020). ©2020 The Authors.

Industrial Relations published by Wiley Periodicals LLC on behalf of Regents of the University of

Californi a (RUC). Published by Wiley Periodicals, Inc., 350 Main Street, Malden, MA 02148, USA, and

9600 Garsington Road, Oxford, OX4 2DQ, UK.

This is an open access article under the terms of the Creative Commons Attribution License, which permits

use, distribution and reproduction in any medium, provided the original work is properly cited.

466

generally fails to adequately control for self-selection, and consequently too

hastily interprets cross-sectional correlations in causal terms.

An emerging literature improves on the previous generation of studies by

making an effort to distinguish between selection and causal effect of union

membership through appropriate research designs. However, the focus of this

new literature is either on particular types of unions—representing longshore-

men (Ahlquist, Clayton, and Levi 2014; Ahlquist and Levi 2013)—or on

workers in industries strongly exposed to the pressures of globalization (Kim

and Margalit 2017), and this makes it difficult to understand the effect of

unions in general. Furthermore, the new literature shares with the old a view

of union membership as an “on/off”switch: when the variable is “on”certain

effects are expected and vice versa when it is “off.”

In this article, we make two contributions: First, we provide a rigorous

assessment of the average treatment effect of union membership on political

attitudes in Switzerland and the UK as a whole (as opposed to membership in

particular unions), carefully distinguishing the effect of attitudinal transforma-

tion—which we refer to as molding—from the selection effect of unions,

which derives from unions having a tendency to attract workers who are sys-

tematically more interested in politics, more likely to participate in elections,

and more willing to vote for labor parties than non-members.

Second, we show that union membership is a process that unfolds in time

before, during, and sometimes after the experience of union membership, and not

just an on/off switch. Using this approach, we uncover an anticipation effect,

which means that in some cases workers begin modifying their attitudes before

joining unions, and a maturation effect, i.e., an attitudinal change which becomes

noticeable only after a certain duration of membership (and thus may fail to mate-

rialize if workers do not remain members for a sufficiently long time). Apprecia-

tion of the dynamic effects of union membership requires longitudinal as opposed

to cross-sectional data, and this is another implication of the article.

Our empirical focus on Swiss and British workers is primarily data driven:

Focusing on Switzerland and the UK allows us to analyze two high-quality

household panel surveys (the Swiss Household Panel [SHP; 1999–2014] and

the British Household Panel [BHPS]/UK Household Longitudinal Study

[UKHLS; 1991–2014]), which are uniquely suited to the type of analysis we

conduct in this article. In particular, they allow us to analyze long union mem-

bership spells. In addition, these two countries provide interesting variation in

both labor and political institutions. With a centralized industrial relations sys-

tem at the industry level and a consensual political system (Lehmbruch 1993;

Lijphart 1998), Switzerland is usually considered a coordinated market econ-

omy (CME; Hall and Soskice 2001), while the UK is widely regarded as a

prototypical liberal market economy (LME). Thus, the choice of these two

A Switch or a Process? / 467

countries provides variation of institutional conditions and boosts the external

validity of results.

1

Nonetheless, as we argue in the Discussion section, the

generalization of our findings to national contexts characterized by predomi-

nantly non-voluntary forms of union membership (e.g., the United States,

Canada) may not be warranted.

The remainder of the article is organized as follows. After discussing the lit-

erature and presenting the theoretical framework in the next section, and the

characteristics of the data in the third, we deliver the empirical analysis in two

parts. In the fourth section, we treat union membership as an on/off switch,

and examine the average treatment effects associated with it. We then shift to

union membership as a process, and analyze how its attitudinal effects vary

dynamically. After providing a discussion of the findings, the final section con-

cludes with limitations of the current research and avenues for future research.

Theoretical Framework

The existing literature on the individual-level impact of trade unions on political

outcomes maintains, almost unanimously, that union membership has important

effects on political attitudes: It increases, on average, the political involvement of

individuals (interest in politics and participation in elections) and their closeness to

left-wing political parties.

2

The bulk of the literature is based on cross-sectional

regressions correlating union membership with political outcomes, while controlling

for some individual and (sometimes) contextual characteris tics. The estimated coeffi-

cients are generally interpreted in causal terms, with (sometimes) a discussion of

why endogeneity should not be considered a problem. Similar results have been

found for several countries, and thus appear robust to cross-national variation (Bry-

son et al. 2013; Bryson 2014; Budd, Lamare, and Timming 2018; D’Art and Turner

2007; Freeman 2003; Geissb¨

uhler 2000; Gray and Caul 2000; Kerrissey and Schofer

2013; Lamare 2010, 2016; Leigh 2006; Leighley and Nagler 2007; Rosenfeld 2010,

2014). In Table A1, Appendix A in supporting information, we provide a summary

of recent studies. In an extension of the classic work on union effects in the United

States (Freeman and Medoff 1984), Freeman (2003) reports that union members are

1

A comparison of Germany and the UK would have been preferable for the purposes of contrasting

CMEs and LMEs. However, in the German Socio-Economic Panel (SOEP) the question on union member-

ship status is only available in some survey years (1985, 1989, 1990, 1993, 1998, 2001, 2003, 2007, 2011,

2015), and hence it is not possible to track continuously the union membership trajectory of an individual

(see Appendix B in supporting information).

2

It should be emphasized that in this article we are interested solely in the individual-level effects of

trade union membership. Unions may have other important effects on politics and policy making qua organi-

zations, but we do not focus on these effects here.

468 / HADZIABDIC AND BACCARO