Collaboration or competition? Experimental evidence for coalition heuristics.

Does coalition formation have a causal effect on the perceived ideological distance between the coalition members? Observational research shows that voters typically think of parties that form a coalition government as more ideologically similar than those that do not, holding everything else constant. Their many qualities aside, the existing studies are not able to establish a causal relationship between coalition formation and changing perceptions. It is quite possible that voters are reacting to concurrent changes in parties' stated policy and not the coalition information itself. In this paper, I present two survey experiments that isolate the difference between telling voters that two parties can cooperate and telling them that they cannot. In both experiments, I find evidence supporting the theory of coalition heuristics. [ABSTRACT FROM AUTHOR]