Projection Bias in the Survey Placement of Spanish Political Parties: Differences between National and Regional Parties

Abstract

This paper estimates the level of projection bias in the issue placement of the main Spanish political parties. We find a different pattern of projection for regional and the main national parties. Whereas assimilation is generalised and homogeneous, contrast is exclusive of the main national parties. We provide indirect evidence that this heterogeneity reflects differences in party acceptability by showing a positive correlation between the party-specific level contrast and the magnitude of non-declared vote. We discuss the implications of our findings for the literature on spatial models and suggest testable hypotheses of why contrast levels vary between regional and national parties.