Constituency preferences and MP preferences: the electoral connection1

Simon Hug2 and Danielle Martin

First version: December 2010, this version: Jan 2, 2011


The question how constituency preferences relate to the preferences of members of parliament has attracted scholarly attention for some time. The relationship between the two sets of preferences is clearly influenced by the mediating electoral system. Empirical studies of this nexus are, however, plague by serious measurement problems. More specifically, most studies rely on more or less similar survey measures for both sets of actors with all the known drawbacks and problems. While behaviorial data may be used in most countries to infer MPs' preferences, similar date fails to exist for voters making up the MPs' constituencies. We employ a novel dataset on voting behavior by MPs in the two chambers of the Swiss parliament which are selected with the help of different electoral systems, and combine this with voting decisions by the constituencies on identical issues in referendums. This allows us to make inferences on the basis of identical behaviorial data, and we find that MPs elected in proportional representation are more widely dispersed around the median voter of their constituencies.


1The Swiss National Science Foundation (Grant No 100012-111909) provided generous funding.

2  Département de science politique, Faculté des sciences économiques et sociales; Université de Genève; 40 Bd du Pont d'Arve; 1211 Genève 4; Switzerland; phone ++41 22 379 83 78; email:

File translated from TEX by TTH, version 3.12.
On 2 Jan 2011, 14:08.