Settlers flocking to boomtowns on the American western frontier were faced with the same task that communities in weak states across the globe face in contemporary times: self-governance. Peer sanctions can enforce cooperation in these environments, but their efficacy depends on the social networks that transmit information from peer to peer. The author uses a game-theoretic model to show that peripheral network positions can generate such strong incentives to misbehave that persistent cheating occurs in equilibrium. The model reveals that groups maintaining high levels of cooperation that face shocks to their strategic environment or to their network can ratchet down into less cooperative equilibria in which the most peripheral become ostracized. Furthermore, population change that features rapid growth, high turnover, and enclave settlements can undermine cooperation. The insights from this article help to explain the trajectory of cooperation in the mining towns of the Wild West in which high levels of cooperation deteriorated as the population surged, and help to make sense of why only certain nonwhite settlers were targets of hostility and racism.

中文翻译：

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为什么西方变得狂野

涌向美国西部边境新兴城镇的定居者面临着与当代全球弱国社区相同的任务：自治。同伴制裁可以在这些环境中加强合作，但其效力取决于在同伴之间传输信息的社交网络。作者使用博弈论模型表明，外围网络位置可以产生如此强烈的行为不端激励，以至于持续的作弊发生在均衡中。该模型表明，在面临战略环境或网络冲击的情况下，保持高水平合作的团体可能会逐渐降低到合作程度较低的平衡，其中最边缘的人会被排斥。此外，以快速增长、高流动性为特征的人口变化，飞地定居点会破坏合作。本文的见解有助于解释狂野西部矿业城镇的合作轨迹，随着人口激增，高度合作恶化，并有助于理解为什么只有某些非白人定居者成为敌对和种族主义的目标。