ABSTRACT
This chapter assesses the organisational incentives that lead non-viable parties to present candidacies alone when they are non-viable. It argues that the overlap of arenas generates two fundamental organisational opportunities that encourage parties to modify their expected strategic entry decisions. First, the superposition of arenas is able to generate political externalities, which may appear in three crucial dimensions that intervene in the development of electoral campaigns, namely, the image that the party projects to voters, the relations of the party central elites with their local organisations and members, and the defence of the party's platform. Second, the superposition of arenas also generates decreasing costs of competing for parties, as the number of constituencies where they present candidacies increases. The chapter argues that the overlap of different electoral arenas generates political externalities that modify parties' entry decisions in contexts of non-viability.
