According to the Duvergerian theories, in the long run, only viable parties are expected to stand for elections. Non-viable parties should join a pre-electoral coalition with another party or withdraw from competition entirely. Why then do non-viable political parties throughout the world systematically continue presenting candidates? This book responds to this evident but unanswered question to create a general theory about deviations from the Duvergerian equilibrium. The author argues that, far from being just a random or irrational decision, the choice of political parties to present candidates when they do not expect to achieve representation can be explained by the overlap of electoral arenas, that generate opportunities for viable parties to present candidates where they are non-viable. In sum, political parties will take advantage of their viability in an arena to present candidacies in other arenas where they do not have chances to become viable. The building of this new theory on electoral contamination allows the construction of a new and more encompassing conceptual framework through which to make sense of what, until now, has been understood as disparate phenomena and contributes to a better understanding of political parties’ strategic behaviour.
’This book provides us with a novel theory to resolve a well-known puzzle in comparative politics: why do parties compete in races they cannot win? It includes valuable new insights to understand strategic party behaviour. This book can inform policy makers and electoral engineers alike about the consequences of overlapping arenas in a system of multi-level governance.’ Thomas Gschwend, University of Mannheim, Germany ’This book constitutes an impressive empirical and theoretical contribution to a better understanding of the logic behind political parties’ decisions to run in non-viable electoral districts under a stable Duvergerian equilibrium. The author shows that the presence of so called contamination effects� between different electoral districts mostly occurs due to the presence of multi-tiered electoral contexts where political arenas overlap. This book is a must� for experts in electoral systems, party systems and comparative politics in general.’ Mariano Torcal, Universitat Pompeu Fabra, Spain