Mean voter representation and partisan constituency representation: Do parties respond to the mean voter position or to their supporters?

TLDR

The study examines whether parties adjust their policies in response to shifts in their supporters’ preferences (partisan constituency model) or to changes in the overall electorate’s mean position (general electorate model), comparing mainstream and niche parties. Cross‑national analysis of Eurobarometer data and party programmes shows that mainstream parties follow the general electorate model, while niche parties align with their supporters’ mean position, underscoring implications for spatial theory and representation.

Abstract

Do political parties respond to shifts in the preferences of their supporters, which we label the partisan constituency model, or to shifts in the mean voter position (the general electorate model)? Cross-national analyses — based on observations from Eurobarometer surveys and parties’ policy programmes in 15 countries from 1973 to 2002 — suggest that the general electorate model characterizes the policy shifts of mainstream parties. Alternatively, when we analyse the policy shifts of Communist, Green and extreme Nationalist parties (i.e. ‘niche’ parties), we find that these parties respond to shifts in the mean position of their supporters. The findings have implications for spatial theories and political representation.