Which way from left to right? On the relation between voters’ issue preferences and left–right orientation in West European democracies

The left–right scale is the concept most often used to describe citizens’ and parties’ political positions. Its prevalence suggests that political preferences are structured by a single ideological dimension. However, much research shows that citizens’ issue preferences in Western Europe are structured by two dimensions: economic; and social–cultural. How can a single dimension be sufficient to orient oneself in a two-dimensional political space? This article suggests a solution to this paradox: among citizens, the left–right scale and more concrete political issues are related in a non-linear way. Economic issue preferences should be more strongly related to ideological differences among left-wing citizens (e.g. between extreme-left and centre-left citizens) than among right-wing individuals. The reverse pattern should characterize the relation between sociocultural issues and ideological self-placement. The analysis of 28 elections in five West European countries offers strong support for the hypothesis of a non-linear relation.