Electoral rule disproportionality and platform polarization

Matakos, Konstantinos and Troumpounis, Orestis and Xefteris, Dimitrios (2016) Electoral rule disproportionality and platform polarization. American Journal of Political Science, 60 (4). pp. 1026-1043. ISSN 0092-5853

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Despite common perception, existing theoretical literature lacks a complete for- mal argument regarding the relationship between the electoral rule disproportionality and platform polarization. In this paper, we build a model that incorporates the disproportionality of the electoral system in a standard Downsian electoral competition setup with mainly, but not necessarily purely, policy-motivated parties. We first show that in equilibrium, platform polarization is decreasing in the level of the electoral rule disproportionality. We then argue that the number of parties has a positive effect on platform polarization when polarization is measured by the distance between the two most distant platforms. This effect does not hold when polarization is measured by the widely used Dalton index. Constructing a dataset covering more than 300 elections, our main theoretical findings are empirically supported, pointing towards the electoral rule disproportionality as a major determinant of polarization.

Item Type:
Journal Article
Journal or Publication Title:
American Journal of Political Science
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This is the peer reviewed version of the following article: Matakos, K., Troumpounis, O. and Xefteris, D. (2016), Electoral Rule Disproportionality and Platform Polarization. American Journal of Political Science, 60: 1026–1043. doi:10.1111/ajps.12235 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/ajps.12235/abstract This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
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13 Nov 2015 16:14
Last Modified:
21 Sep 2023 01:56