Regional inequality and institutional trust in Europe

Inequality is a central explanation of political distrust in democracies, but has so far rarely been considered a cause of (dis-)trust towards supranational governance. Moreover, while political scientists have extensively engaged with income inequality, other salient forms of inequality, such as the regional wealth distribution, have been sidelined. These issues point to a more general shortcoming in the literature. Determinants of trust in national and European institutions are often theorized independently, even though empirical studies have demonstrated large interdependence in citizens’ evaluations of national and supranational governance levels. In this paper, we argue that inequality has two salient dimensions: (1) income inequality and (2) regional inequality. Both dimensions are important antecedent causes of European Union (EU) trust, the effects of which are mediated by evaluations of national institutions. On the micro-level, we suggest that inequality decreases a person's trust in national institutions and thereby diminishes the positive effect of national trust on EU trust. On the macro-level, inequality decreases country averages of trust in national institutions. This, however, informs an individual's trust in the EU positively, compensating for the seemingly untrustworthiness of national institutions. Finally, we propose that residing in an economically declining region can depress institutional trust. We find empirical support for our arguments by analysing regional temporal change over four waves of the European Social Survey 2010–2016 with a sample of 209 regions nested in 24 EU member states. We show that changes in a member state's regional inequality have similarly strong effects on trust as changes in the Gini coefficient of income inequality. Applying causal mediation techniques, we can show that the effects of inequality on EU trust are largely mediated through citizens’ evaluations of national institutions. In contrast, residing in an economically declining region directly depresses EU trust, with economically lagging areas turning their back on European governance and resorting to the national level instead. Our findings highlight the relevance of regional inequality for refining our understanding of citizens’ support for Europe's multi-level governance system and the advantages of causal modelling for the analysis of political preferences in a multi-level governance system.