AI 中文总结
该研究探讨疏离感弃权下政党趋同的持续性，提出向心结构概念，证明其可实现均衡趋同，且一旦出现便会持续，还能对政策导向政党的均衡完全分类。
AI 中文摘要
在标准的唐斯模型中，两个追求职位的政党会向中位选民趋同。然而，感到疏离的选民可能会弃权（不执行），仅投票给在其容忍半径内的政党。对于单峰选民分布，趋同会持续存在，但会转移到参与趋同平台的选民的中位数，即中位选民。不过，选民分布的单峰性是一个经验上有争议的假设。因此，我们首先为任何连续选民分布刻画纯策略均衡。对于一般分布，纯策略均衡可能不存在或不唯一，且均衡的存在性不一定会随选民容忍半径的增大而持续。为解决这些问题，我们提出一个核心概念：向心结构，即存在一个单一的锚定平台，竞争始终会将各方拉向该平台。我们表明，该结构会在基于疏离感弃权的情况下产生均衡趋同。我们的主要结果涉及随着容忍半径增大，这种新结构的出现与持续存在：尽管追求职位的政党的均衡本身可能会随半径增大而消失和重现，但向心结构一旦出现，只要中点选民未被疏离，就会持续存在。此外，向心结构总会出现，且当政党以政策为导向时，该结构可完全对均衡进行分类。
英文摘要
In the standard Downsian model, two office-seeking parties converge to the median voter. However alienated voters may abstain and turn out only for a party within their tolerance radius. For single-peaked voter distributions, convergence survives but relocates to a central voter, the median of the electorate that participates at the convergent platform. However single-peakedness of the voter distribution is an empirically contested assumption. So we first characterize pure-strategy equilibrium for any continuous voter distribution. For general distributions, pure-strategy equilibrium can fail to exist or be non-unique, and existence of equilibrium need not persist as the tolerance radius of the voters increases. In order to resolve these issues, we propose a fundamental object: \emph{centripetal} structure for which there is a single anchor platform toward which competition always pulls. We show this structure produces convergence at equilibrium under alienation based abstention. Our main result concerns the emergence and persistence of this new structure as the tolerance radius increases. Even though equilibria for office-seeking parties themselves can vanish and reappear as the radius grows, once centripetal structure emerges, it persists as long as the midpoint voter is not alienated. Moreover, the centripetal structure always emerges, and this structure classifies equilibrium completely when parties are policy motivated.
Comments51 pages, 6 figures
