This paper analyzes how accurately citizens perceive parties’ electoral chances. It is often assumed, for example in studies of strategic voting, that citizens’ perceptions of parties’ electoral chances are correct on average. Previous research has however shown that citizens are affected by wishful thinking. They tend to overestimate the chances of their preferred party. Previous research on this topic has mainly focused on majoritarian electoral systems. This paper extends this line of research by considering the accuracy of citizens’ perceptions in both majoritarian and proportional electoral systems. It also considers two different sources of bias: partisan and ideological preferences. The analysis is based on pre-electoral internet surveys conducted in several countries, for both national and local elections, in the framework of the MEDW project. The paper analyzes the relative impact of partisan and ideological bias, how they are conditioned by political sophistication, and how these effects vary between institutional contexts.
