What is the issue content of experts’ placements of parties on the left-right dimension? The structure of the political space in Western democracies has changed substantially in past decades. New issues and the strategies of challenger parties have raised the salience of the socio-cultural dimension, and led to a relative decrease in the importance of the economic dimension. These changes also result in a more complex configurations of party positions – a development that underscores the multidimensionality of the political space. Most common is to represent that space as structured by two dimensions (economic and socio-cultural).
Yet, despite this growing complexity, the left-right scale remains meaningful. It is a central heuristic to distinguish between party (and voter) positions, and there seems to be a shared understanding of that dimension. This is surprising, as the left-right dimension should not be sufficient to meaningfully summarize the positions of parties in a genuinely multidimensional space. As a solution to that paradox, this paper suggests that the left-right dimension is related in a non-linear manner to the underlying economic and socio-cultural dimensions: left-wing parties differ mainly in their economic positions, and right-wing parties on the cultural dimension. The one-dimensional left-right scale thus captures variation in two dimensions.
The paper tests this hypothesis by analyzing how parties’ left-right positions, as assessed by experts, are associated with their issue-specific positions (combining data from various sources: CHES, CSES, GPS, CMP). Results show the expected non-linear pattern and invite us to rethink our interpretation of the left-right dimension.