Under the assumption that a voter's utility is maximized when s/he chooses the candidate/party that is closest to the voter's own most preferred set of policies, the Downsian proximity model of voter choice has become the standard method for modeling the linkage between the policy preferences of...

In two-party competition, it is well known that the party whose supporters/identifiers are more ideologically concentrated can pull the overall median in the direction of its party median, while the overall mean is essentially simply an average of the two party means weighted by the number of...

The standard Downsian model of two-party competition cannot account for the well-known fact that incumbents rarely lose elections. This paper modifies the model to take account of the tendency for voters to give the incumbent the `benefit of the doubt'; i.e. voters may vote for an incumbent even...

We present some basic results concerning the spatial theory of voting in such a way that the theorems and their proofs should be accessible to a broad audience of political scientists. We do this by making the presentation essentially geometrical. We present the following results in particular:...

The Laakso-Taagepera index (Laakso and Taagepera, 1979) has become the most commonly used measure to specify the ‘effective’number of political parties in a party system where parties vary substantially in their vote and/or seat shares. It is well known that the Laakso-Taagepera...

While there are many formal models that generate predictions about polarization, only a handful address the question of how, with no change in electoral rules, levels of polarization can dramatically vary over time, as they have in the US House during 150 years of two-party competition. We...