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The Electoral Consequences of Party Switching in Canada: 1945–2011

  • Feodor Snagovsky (a1) and Matthew Kerby (a1)


This article addresses the overlooked subject of party switching in the Canadian House of Commons for the period 1945–2011. We estimate a model that explores how and why MPs engage in the otherwise risky behaviour of abandoning their party labels in a system characterized by a low personal vote. Our findings suggest that the electoral consequences for MPs who switch parties for policy reasons are indistinguishable from MPs who do not switch at all. By contrast, MPs who switch parties for office-related reasons, such as to accept a seat in cabinet or vote-related reasons, experience large electoral penalties. We also find that MPs who are expelled from caucus face the strongest electoral penalties of all party switchers, indicating it matters whether an MP jumps or is pushed. Our findings suggest that voters recognize opportunistic behaviour among their legislators and punish them accordingly and that under some circumstances, party switching may be both strategic and rational.

Cet article aborde le sujet négligé du changement de parti au sein de la Chambre des communes canadienne pour la période comprise entre 1945 et 2011. Nous estimons le modèle qui examine les raisons pour lesquelles les députés adoptent le comportement par ailleurs périlleux d'abandonner l’étiquette de leur parti dans un système caractérisé par le peu de poids qu'a le vote personnel. D'après nos constatations, les conséquences électorales touchant les députés qui changent d'allégeance pour des raisons politiques sont impossibles à distinguer de celles des députés qui ne l'envisagent en aucun cas. En revanche, les députés qui changent de parti pour des raisons liées à leur fonction, lors par exemple de l'acceptation d'un siège au conseil des ministres, ou bien dictées par un vote subissent de lourdes sanctions électorales. Nous constatons également que, parmi les députés qui changent de parti, les députés expulsés de leur groupe parlementaire sont sanctionnés le plus lourdement, en indiquant l'influence qu'exerce le fait de faire le saut ou d'y être poussé. Nos conclusions suggèrent que les électeurs reconnaissent un comportement opportuniste parmi leurs législateurs et les punissent en conséquence et que dans certaines circonstances, le changement de parti est motivé par des raisons aussi bien stratégiques que rationnelles.


Corresponding author

Australian National University, Acton ACT 2601, Australia, email:
Australian National University, Acton ACT 2601, Australia, email:


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Acknowledgments: The authors would like to thank the editors and reviewers of the Journal for their helpful comments and suggestions as well as Hwan-Jin Yoon, Daniel Stockemer, André Lecours, Luc Turgeon and Marina McGale. An earlier version of this article was presented at the 2015 Midwest Political Science Association Annual Conference.



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The Electoral Consequences of Party Switching in Canada: 1945–2011

  • Feodor Snagovsky (a1) and Matthew Kerby (a1)


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