We introduce a model of group behavior that combines expressive participation with strategic participation. Building on the idea that expressive voting in elections is much like rooting for a sports team, we give applications to both sporting events and elections. In our model there is an expressive externality: an individual enjoys an event more when more of her peers come out to support her preferred party or team. We show that this results in the possibility of “tipping”—that participation may jump up discontinuously when the externality becomes strong enough. We examine the implications for pricing by sports teams and for voter turnout.

中文翻译：

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双峰：群体参与中的表现性外部性

我们引入了一种将表达性参与与策略性参与相结合的群体行为模型。基于选举中的表达性投票就像支持运动队一样的理念，我们向体育赛事和选举提供申请。在我们的模型中，存在一种表现性的外部性：当更多的同龄人站出来支持她喜欢的政党或团队时，个人会更喜欢某项活动。我们证明，这会导致“倾斜”的可能性——当外部性变得足够强时，参与度可能会不连续地上升。我们研究了运动队定价和选民投票率的影响。