Over the past four decades, mass political behaviour in Western democracies has undergone a major transformation marked by a shift from the traditional gender gap to the modern gender gap. Before the 1980s, women were stronger supporters of right-wing parties than men (Dogan Reference Dogan1967; Duverger Reference Duverger1955; Lipset Reference Lipset1960), but since then they have become increasingly more likely than their male counterparts to vote for left-wing parties (Abendschön and Steinmetz Reference Abendschön and Steinmetz2014; Giger Reference Giger2009; Inglehart and Norris Reference Inglehart and Norris2003).
Scholars have offered compelling explanations for this phenomenon. Cultural theories alluded to the process of modernization experienced by post-industrial societies, and the proliferation of post-materialist values of equality between the sexes – mainly, but not exclusively, among women citizens – (Emmenegger and Manow Reference Emmenegger and Manow2014; Inglehart and Norris Reference Inglehart and Norris2003; Shorrocks Reference Shorrocks2018). Structural theories, on the other hand, focused on women’s growing economic empowerment and its implications for gender relations, household organization, and the types of welfare policies that women and men tend to prefer (Carroll Reference Carroll1988; Iversen and Rosenbluth Reference Iversen and Rosenbluth2006; Manza and Brooks Reference Manza and Brooks1998).
Both cultural and structural theories of the gender voting gap highlight the prominent role of women’s entry into the formal workforce in the second quarter of the twentieth century. Since 1960, most Western countries have experienced significant increases in women’s labour force participation rates (Costa Reference Costa2000) due to the growing aggregate demand for female workers, the expansion of part-time work, and the greater inclusion of women in the education system (Goldin Reference Goldin2006). Women’s employment affects the gender voting gap through diverse pathways: it exposes women to novel forms of discrimination in the workplace, fostering an attitudinal shift towards more egalitarian gender-role values (Andersen and Cook Reference Andersen and Cook1985; Inglehart and Norris Reference Inglehart and Norris2003; Rindfuss, Brewster, and Kavee Reference Rindfuss, Brewster and Kavee1996; Togeby Reference Togeby1994); it puts women in contact with peers and mobilizing agents such as labour unions (Norris Reference Norris2002); and it increases women’s economic autonomy vis-à-vis men (Carroll Reference Carroll1988; Iversen and Rosenbluth Reference Iversen and Rosenbluth2006). As Iversen and Rosenbluth point out, working women tend to vote for left-wing parties more than men do because the policies those parties promote in the domain of welfare – namely, public investment in work-family services – socialize the burden of domestic work that falls on women’s shoulders under patriarchal arrangements. This allows women to invest their time in developing marketable skills and increases their bargaining power at home relative to their partners.
Taken together, these arguments imply that a larger gender gap in the vote for left-wing parties should be observed as female labour force participation rises. Figure 1 leverages public opinion and International Labour Organization (ILO) data from sixteen Western European democracies between 1985 and 2019. It illustrates that, although the prediction of previous research is accurate in the aggregate (A) when analyzed on a country-to-country basis, there is significant variation in the shape and size of the gender voting gap (B), even among countries with similar rates of female labour force participation (FLFP) over time. Notably, we see differences not only between countries but also within countries across time.
Figure 1. The gender voting gap in Western Europe. Solid lines represent LOESS curves illustrating the ratio of the share of women voters for a specific left-wing party to the share of men who voted for the same party. The dotted lines indicate female labour force participation rates. Left-wing parties encompass the largest Ecological, Socialist, and Social Democratic parties in each election: (a) Pooled sample, (b) Country samples.
Source: Comparative Study of Electoral Systems, European Social Survey, European Election Study, Comparative Manifesto Project, and the International Labor Organization. Design weights applied.
Variation in the gender voting gap is not new but prevalent in cultural and structural studies. Inglehart and Norris (Reference Inglehart and Norris2003, 11) acknowledged it, suggesting that ‘industrialization brings broadly similar trajectories, even if situation-specific factors make it impossible to predict exactly what will happen in a given society’. Similarly, Giger (Reference Giger2009, 486) argued that the driving force for the emergence of the gender voting gap in Western Europe is increased levels of female labour participation, but observed that ‘the pace of gender realignment differs across European countries’. Abendschön and Steinmetz (Reference Abendschön and Steinmetz2014, 315) also confirmed the relevance of women’s workforce participation for the gender voting gap but documented that ‘[i]ts size, however, varies across countries’.
How can we explain this variation? This article aims to answer this question by focusing on a piece of this puzzle that has been overlooked by previous research on the gender voting gap: the role played by political parties and, specifically, the extent to which they represent working women’s interests. The argument is simple: women’s growing presence in the labour force might create a demand for representation in the form of welfare policies, but the final shape of the gender voting gap should depend on the extent to which parties advocate for such policies. Despite mounting comparative evidence that women are more supportive of the welfare state than men (Weeks Reference Weeks2022) and solid theoretical reasons to expect working women to vote for left-wing parties more than men (for example, Iversen and Rosenbluth Reference Iversen and Rosenbluth2006), no study has yet assessed whether the gender voting gap is larger for left-wing parties that are more supportive of gender-egalitarian policies in the labour market compared to those who are less supportive of these policies. Empirical evidence of this claim is a necessary piece of the gender voting gap puzzle that political science is still lacking.
This note provides such a test by drawing on three decades of public opinion, expert surveys, and macroeconomic data. Multilevel regressions further support the association between female labour force participation and the female-to-male voter ratios of left-wing parties; however, this correlation is positive only when left-wing parties strongly endorse gender labour equality. These findings have important implications for the way we think about the gender voting gap and elevate party behaviour as a key factor behind it.
Employment and the Gender Voting Gap
There is a rich literature in political science examining women’s and men’s turnout in elections (for example, Dassonneville and Kostelka Reference Dassonneville and Kostelka2021; Teele Reference Teele2022; Verba, Nie, and Kim Reference Verba, Nie and Kim1978), political engagement and activism (for example, Beauregard Reference Beauregard2014; Coffé and Bolzendahl Reference Coffé and Bolzendahl2010; Kittilson and Schwindt-Bayer Reference Kittilson and Schwindt-Bayer2012), political interest and ambition (for example, Bos et al. Reference Bos, Greenlee, Holman, Oxley and Lay2022; Clayton, O’Brien, and Piscopo Reference Clayton, O’Brien and Piscopo2024; Coffé Reference Coffé2013), and political attitudes (for example, Barnes and Cassese Reference Barnes and Cassese2017; Bush and Clayton Reference Bush and Clayton2023; Inglehart and Norris Reference Inglehart and Norris2003; Iversen and Rosenbluth Reference Iversen and Rosenbluth2006; Weeks Reference Weeks2022). The concept of the gender voting gap refers to differences in the vote choices of men and women (Coffé et al. Reference Coffé, Kittilson, Meguid and Weeks2023; Kittilson Reference Kittilson2016; Weeks et al. Reference Weeks, Meguid, Kittilson and Coffé2022). It acquired special relevance in the 1980s when Western women gradually became more supportive of left-wing parties than men (Inglehart and Norris Reference Inglehart and Norris2003).
Most research on the gap converges on the idea that female employment lies at its core. This is not a straightforward correlation and should be conceptualized as a process with multiple layers. Some authors argue that formal employment changed women’s attitudes toward gender equality, which then shaped their political behaviour (Andersen and Cook Reference Andersen and Cook1985; Inglehart and Norris Reference Inglehart and Norris2003; Rindfuss, Brewster, and Kavee Reference Rindfuss, Brewster and Kavee1996; Togeby Reference Togeby1994). Inglehart and Norris (Reference Inglehart and Norris2003) posit that economic development gradually shifted Western citizens’ values toward post-materialist ideals of freedom, self-expression, and equality between the sexes, particularly among women and the youngest generations. Modernization brought new job opportunities for women and has been accompanied by a process of secularization, which had a stronger impact on women’s values, policy positions, and vote choices than on men’s (Emmenegger and Manow Reference Emmenegger and Manow2014; Shorrocks Reference Shorrocks2018). Women face strong inequalities in labour markets and workplaces, which, it is argued, increases their demand for gender equality (Togeby Reference Togeby1994). Early evidence from the United States showed that working women were more likely than housewives to believe in a women’s equal role in running a business, industry, and government; they also tended to disagree more with the idea that women should be the first workers to be laid off (Andersen and Cook Reference Andersen and Cook1985) and that children of working women suffer more (Rindfuss, Brewster, and Kavee Reference Rindfuss, Brewster and Kavee1996).
Work also shapes the gender voting gap through its influence on women’s resources, which are key for political participation (Brady, Verba, and Schlozman Reference Brady, Verba and Schlozman1995; Burns, Schlozman, and Verba Reference Burns, Schlozman and Verba2001; Norris Reference Norris2002). For example, rising female labour force participation rates correlate with greater citizen political engagement, as evidenced by increased discussion, heightened political interest, persuasion, the contacting of politicians, and more frequent voting (Kittilson and Schwindt-Bayer Reference Kittilson and Schwindt-Bayer2012).
Households constitute an arena of interest for the gender voting gap due to the constraints that an unequal gender distribution of household labour imposes on women’s political behaviour. Women demobilize from politics during pregnancy in ways that men do not, and this gap in political engagement strengthens during the earliest stages of parenthood (Naurin, Stolle, and Markstedt Reference Naurin, Stolle and Markstedt2023). Furthermore, breadwinning responsibilities negatively affect women’s political ambition, especially for mothers (Bernhard, Shames, and Teele Reference Bernhard, Shames and Teele2021). Women also carry most of the cognitive household labour, which prevents them from engaging with news about politics and political discussion (Weeks Reference Weeks2024). Those imbalances become more pronounced when women’s life prospects are closely linked to their partners. That is because women’s material and psychological autonomy lies at the heart of the gender voting gap (Carroll Reference Carroll1988; Iversen and Rosenbluth Reference Iversen and Rosenbluth2006).
In their canonical work, Iversen and Rosenbluth posit that gender differences in voting behaviour are shaped by household dynamics, which are greatly influenced by the distribution of material resources between partners. These authors demonstrated that there are few differences in the policy preferences of men and non-working women; however, differences arise as women join the workforce. Iversen and Rosenbluth argue that female employment breaks the male breadwinner logic of women’s material dependence on men and increases women’s bargaining power at home over household decisions and the distribution of household work. Working women are thus more likely to advocate for policies that increase their outside marriage options – such as public investment in childcare and improvements in maternity leave schemes – because they socialize the burden of domestic work that falls on their shoulders under patriarchal arrangements, allowing women to invest their time outside the household. Men, conversely, tend to be more concerned about the fiscal impact of those policies. The result is a gender gap in policy preferences that has been thoroughly documented by comparative research (Weeks Reference Weeks2022).Footnote 1 Since left-wing parties tend to support welfare expansion, Iversen and Rosenbluth argue that working women become more likely than men to vote for them.
Women’s Substantive Representation and the Gender Voting Gap
While women’s labour force participation and the gender voting gap are positively correlated in the aggregate, this association becomes less clear in cross-country comparisons (Fig. 1). Most of the change in women’s workforce participation occurred before the mid-2000s, whereas a sharp uptick in the gender voting gap emerged in many countries from 2010 onwards. Furthermore, the gender voting gap fluctuates from one election to another, unlike the more stable trends in women’s employment. This suggests that the relationship between these two factors is not linear and may be contingent upon aspects of each election.
Research on gender and politics has long underscored the pivotal role played by contexts in shaping gender differences in political behaviour. For example, inclusive institutions such as proportional representation electoral systems and mechanisms of direct democracy enhance women’s political engagement and participation more than men’s (Kim Reference Kim2019; Kittilson and Schwindt-Bayer Reference Kittilson and Schwindt-Bayer2010; Skorge Reference Skorge2021; Teele Reference Teele2022). Moreover, higher levels of political efficacy, engagement, and participation are reported among women when female candidates are more visible in electoral campaigns and when there is an increased presence of women in parliament (Atkeson and Carrillo Reference Atkeson and Carrillo2007; Campbell and Wolbrecht Reference Campbell and Wolbrecht2006; Wolbrecht and Campbell Reference Wolbrecht and Campbell2007).
When it comes to gender differences in vote choice, a key contextual factor refers to the behaviour of political parties, particularly, how much left-wing parties champion policies that promote gender equality in the labour market. Even in the presence of a gender gap in preferences towards welfare (Iversen and Rosenbluth Reference Iversen and Rosenbluth2006; Weeks Reference Weeks2022), it is still on parties to address those demands and supply those policies. Implicit in previous studies is the idea that all left-wing parties are strong supporters of welfare expansion. Although that is true in comparison to parties on the right and centre (Kittilson Reference Kittilson2011), it overlooks the fact that left-wing parties differ in the extent to which they support such policies (Figures A1 and A2). Consequently, parties’ substantive representation of women could serve as the missing link that connects the well-known shifts in public opinion highlighted by previous research to the large variation observed in the gender voting gap.Footnote 2 I build on this fact to formulate two hypotheses. The first is the classical conjecture linking women’s workforce participation to the gender voting gap.
-
${H_1}$
(Classical hypothesis): As female labour force participation increases so does the female/male voter ratio for left-wing parties.
The second hypothesis adds the moderating effect of the parties’ policy positions, the main intended contribution of this article. It aims to show that the association proposed in
${H_1}$
should be conditional on parties’ advocacy for gender labour equality.
-
${H_2}$
(Party behaviour moderation): The association between female labour force participation and the female/male voter ratio will be stronger for left-wing parties that are more supportive of gender egalitarian policies in the labour market.
Empirical Approach
To test my argument, I rely on data from the Comparative Study of Electoral Systems (CSES), the European Election Study (EES), and the European Social Survey (ESS), which ask respondents about their vote in the last national election.Footnote
3
I use these data to build an original dataset at the party-election level covering the period 1990–2019. Following Weeks et al. (Reference Weeks, Meguid, Kittilson and Coffé2022), I estimate the female-to-male party voter ratio
$(F/M)$
, which I use as my measure of the gender voting gap. For a party i in an election year t, I computed:
$$F{\rm{/}}{M_{it}} = {{(N\;\;{\rm{women}}\;{\rm{voting}}\;{\rm{for}}\;{\rm{party}}\;i\;{\rm{in}}\;{\rm{election}}\;t/N\;{\rm{women}}\;{\rm{voters}}\;{\rm{in}}\;{\rm{election}}\;t)} \over {(N\;{\rm{men}}\;{\rm{voting}}\;{\rm{for}}\;{\rm{party}}\;i\;{\rm{in}}\;{\rm{election}}\;t/N\;{\rm{men}}\;{\rm{voters}}\;{\rm{in}}\;{\rm{election}}\;t)}}.$$
Values over 1 mean that women have a relatively higher presence in a party’s electorate than men.Footnote 4 I restrict my analyses to left-wing parties, which are those from the Comparative Manifesto Project’s Ecological, Socialist, and Social Democratic families (N = 248 party elections).Footnote 5 Since the distribution of the resulting ratio is right-skewed, I use its logarithm as an outcome variable.Footnote 6
The main explanatory variable of this study is an indicator of parties’ support for measures promoting the equal participation of women in the labour market, taken from the V-Party dataset (Hindle and Lindberg Reference Hindle and Lindberg2020). V-Party is a collaboration of more than 700 experts who assessed different features of most parties in the participating countries, starting in 1970. To produce this indicator, experts were asked to what extent each party in a specific election supported legal provisions for equal treatment, pay, parental leave, and financial support for childcare. V-Party specialists used the answers to those questions to fit ordinal IRT models, generating a continuous latent variable that reflects a party’s overall commitment to gender labour equality.Footnote 7 When it comes to answering my research question, the V-Party indicator has important advantages over similar measures such as the Comparative Manifesto Project’s ‘welfare state expansion’ (per504) indicator (Volkens et al. Reference Volkens, Burst, Krause, Lehmann, Matthieß, Merz, Regel, Weßels and Zehnter2020) because it taps into the specific dimension of welfare that Iversen and Rosenbluth (Reference Iversen and Rosenbluth2006), identified as relevant for the gender voting gap.Footnote 8
The second explanatory variable of interest is a measure of women’s workforce participation. I use the International Labor Organization’s measure of female labour force participation rates (FLFP), which captures the proportion of the female population aged fifteen and older that is economically active (ILO 2023). I lag this indicator one year to measure its impact on election outcomes.Footnote 9
Identification Strategy
I test my hypotheses using linear mixed-effects models with random intercepts for country years (that is, elections) and parties. In line with previous research, these models assume that the gap is a consequence of changes in country-level variables over time. I use random intercepts for parties to capture variations in the gap due to the unobserved characteristics of each party.
The strategy I follow to identify the effect of FLFP and parties’ gender labour equality positions on the gender voting gap is controlling for a set of theoretically relevant covariates able to block plausible back-door paths between my explanatory variables and the outcome (Keele, Stevenson, and Elwert Reference Keele, Stevenson and Elwert2020).Footnote 10 First, I control for the OECD’s (2023) measure of the divorce rate, which is the number of divorces during a given year per 1,000 people. I lag this variable for one year. I also control for the percentage of the population that adheres to Christianity at the time of the election, extracted from the World Religion Dataset (WRD) (Maoz and Henderson Reference Maoz and Henderson2019).Footnote 11 At the party level, I control for two confounders of the relation between party positions and the gender voting gap: the share of women in the parliament party and the presence of a female party leader, variables borrowed from Weeks et al. (Reference Weeks, Meguid, Kittilson and Coffé2022), and lagged one election year.Footnote 12
I estimate three models, which iteratively display my argument. When analyzing them, I pay special attention to both the estimated coefficients for the explanatory variables and the differences in the variance of the random components across models. Model 1 includes structural and cultural variables – on which most of the literature on the gap has focused – providing a direct test of
${H_1}$
. Model 2 adds party-level indicators. Model 3 interacts with the V-Party indicator of gender labour equality with FLFP to test
${H_2}$
.
Results
Table 1 presents the results. Consistent with previous research, Model 1 shows that FLFP rates are positively associated with the gender voting gap.
$({\rm{p}} \lt 0.01)$
, evidence that supports
${H_1}$
. We see that most of the variation in the outcome comes from the party and party-election levels (
${\hat \sigma ^2}_{{\rm{party}}} = 0.039$
, and
${\hat \sigma ^2}_{{\rm{residual}}} = 0.06$
).
Table 1. Determinants of the gender voting gap
+p < 0.1; *p < 0.05; **p < 0.01; ***p < 0.001.
Model 2 introduces the party-level indicators. Results already suggest that parties’ positions on gender labour equality are meaningful for the gender voting gap: those two variables are positively correlated
${\rm{(p}} \lt 0.1)$
, the coefficient for FLFP becomes indistinguishable from zero, and both the party and the residual-level variances decrease.
Model 3 confirms those intuitions. Consistent with
${H_2}$
, the interaction coefficient – the main focus of this article – is positive and statistically significant
${\rm{(p}} \lt 0.01)$
. Also consistent with
${H_2}$
is the sign of the FLFP coefficient: when left-wing parties’ positions on gender labour equality are at their minimum, increases in FLFP rates are not associated with more support from women voters relative to men.Footnote
13
To better interpret the interaction coefficient of Model 3, Fig. 2 plots the marginal effect of FLFP across different levels of parties’ support for gender labour equality. Women’s participation in the labour market is positively associated with larger gender voting gaps for left-wing parties, but only when those parties are strong advocates of gender labour equality. For instance, around a quarter of the sample (FA3) – predominantly consisting of Ecological parties, but also including parties from the Socialist and Social Democratic families (FA1) – scores more than 2.7 on the gender labour equality indicator. In those cases, a ten-point increase in FLFP results in a 20 per cent increase in
$F/M$
. Conversely, when left-wing parties offer limited support for these policies, the association between women’s workforce participation and the gender voting gap becomes negative, resulting in the electorates of these parties becoming more masculinized.
Figure 2. The marginal effect of FLFPt−1 across different levels of parties’ support for gender labour equality. Estimated coefficients based on Model 3, with 95 per cent confidence intervals.
Source: CSES, ESS, EES, ILO, and V-Party.
Robustness tests in Appendix 3 confirm that the results remain stable under different specifications, such as models adding country random effects, which assume that elections are nested in countries. Consistent results are found after controlling for other features of elections that could affect the
$F/M$
ratio of left-wing parties, such as the behaviour of other parties, economic hardship (Shorrocks and Grasso Reference Shorrocks and Grasso2020), the share of the rural population (Teele Reference Teele2024), parties’ incumbency status, alternative lag structures for the main variables, and models removing outliers. Conditional logistic regressions of vote choice yield similar results, even accounting for voters’ demographics, socio-economic status, religiosity, and gender values. Further analyses at the individual level uncover differences across occupational groups of voters, notably a positive impact of parties’ gender labour equality positions on middle-class women’s vote choices and a more nuanced effect on middle-class men’s, which align with the expectations from resource theories of the gap.
Conclusion
The gender voting gap has received a great deal of attention from scholars, who have positioned women’s participation in the labour force as one of its main drivers. The second half of the twentieth century saw a rise in female employment in Western democracies, which altered gender relations (Inglehart and Norris Reference Inglehart and Norris2003; Iversen and Rosenbluth Reference Iversen and Rosenbluth2006); since then, left-wing parties in the region have tended to receive more electoral support from women than from men. However, a great deal of variation in the shape of the gap across and within countries remains unexplained.
This article brings political parties to the forefront of the study of the gender voting gap, showing that its shape responds to differences in left-wing parties’ welfare positions. Findings only confirm the established association between women’s employment and the gap when left-wing parties embrace policies of gender equality in the labour market. Party behaviour is therefore key to understanding gender differences in vote choice, which should be a focal point in future research on gender and political behaviour.
Future research could build upon these findings to explore how party competition influences the gender voting gap. The late-twentieth century witnessed the emergence of new left-wing contenders such as Ecological parties, impacting the strategies of Social Democratic parties (Kitschelt Reference Kitschelt1994). As this note shows, Social Democratic parties differ in their support for gender labour equality (FA2), which could respond to the different electoral incentives they face across countries. Research could also investigate how party behaviour impacts different groups of women and men voters; for instance, depending on their class. That would require developing fine-grained measures of party behaviour that tackle specific dimensions of welfare relevant for voters according to their social strata (see Appendix 3). As gender differences in political attitudes grow more salient in public discourse, understanding the influence of political parties on the gender voting gap becomes essential.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S0007123424000425.
Data availability statement
Replication data for this article can be found in Harvard Dataverse at: https://doi.org/10.7910/DVN/321H1X.
Acknowledgements
I want to thank Diana Z. O’Brien, Randolph T. Stevenson, Leslie Schwindt-Bayer, and Jonathan Homola for their invaluable feedback. I would also like to thank the editor and the anonymous reviewers for their helpful comments and suggestions during the review process.
Financial support
None.
Competing interests
None.
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