Ideological proximity and valence competition. Negative campaigning through allegation of corruption in the Italian legislative arena from 1946 to 1994

We consider the possibility for the parties to invest in negative campaigning – a behavior that, in our framework, involves blaming alleged insufficiencies of the rival concerning commonly shared values. Within a simple one-dimensional model, we deduce the hypothesis that the parties’ incentive to “attack” each other increases with the parties’ proximity on the left–right space. We test our hypothesis on an Italian case, focusing on the emphasis placed by the Communist Party on political corruption issues during the government investiture debates that spanned from the postwar period until 1994, when the traditional party system abruptly collapsed. The statistical results are largely consistent with our theoretical insights.