Synergy in Spatial Models of Voting: How Critical Cases Show ThatProximity,DirectionandDiscountingAre Friends, Not Foes

The spatial theory of elections is widely used to examine how party policy is linked to voter preferences. Three classic models – proximity, direction and discounting – lay claim to the nature of this link, but their predictions of voting behavior are almost identical. I resolve the problem by decomposing 28 multi-party systems into about 1 million party triplets. This allows me to isolate “critical cases” where model predictions diverge. The combinatorial approach reveals a degree of collinearity between models that may surprise even longtime experts in the field. But while collinearity is a nuisance for scholars, it is a blessing for voters. I find disproportionately strong policy voting when all predictions agree, indicating that there is synergy between the three spatial logics. A selection effect can be excluded using propensity-score matching. These findings suggest that concurrence of proximity, directional and discounting elements in the vote function is inherent to electoral competition.