Third Parties, Turnout, and Social Influence Why Third Party Entry May Decrease Turnout in Plurality Systems

Interpersonal social networks play a critical role in increasing turnout through voter cooperation and coordination. However, different contexts and institutions can inhibit this type of coordination by increasing voter uncertainty. We examine one mechanism by which third party entry in plurality voting systems might decrease turnout by increasing voter confusion about the political preferences of their fellow citizens. We extend the Fowler Turnout in a Small World model [18], providing theoretical evidence that voters may be disincentivized to turn out under three party competition in single member district plurality systems. Finally, we support our theoretical work with an examination of turnout in modern British elections, which provides empirical support for our theoretical findings.