Political mobilisation and socioeconomic inequality in policy congruence

In recent years, scholars have observed that political parties’ policy positions frequently fit the preferences of well-to-do voters better than those of the less well-to-do; a phenomenon known as policy congruence inequality. While the existence of inequality in policy congruence is well-established, we currently only have a modest understanding of the causes of it. We develop an argument proposing that the political mobilisation of citizens with low socioeconomic status (SES) both in the parliamentary channel, in the form of high turnout, and in the extra-parliamentary channel, in the form of high union density, is pivotal. Both high turnout and union density force parties to pay more attention to the preferences of the disadvantaged, thereby creating lower policy congruence inequality. To test the argument, we have collected and harmonised election surveys and party manifestos covering 90 elections in Australia, Denmark, Germany, Sweden, Switzerland, the United Kingdom and the United States, covering several decades until today, yielding more than 120,000 voter–party dyads. Employing this new dataset, our results confirm that the political mobilisation of citizens with low SES is a strong predictor of policy congruence inequality. This finding nuances the conclusion of extant research by showing that low-SES citizens are not always on the losing side politically. It also implies the important role of maintaining or maybe even increasing turnout and union membership among the disadvantaged in society. Places where either turnout or union density is slipping in these years are likely to witness further increases in policy congruence inequality in the years to come.