We investigate if there is a peer influence or role model effect on successful graduation from Therapeutic Communities (TCs). We analyze anonymized individual-level observational data from 3 TCs that kept records of written exchanges of affirmations and corrections among residents, and their precise entry and exit dates. The affirmations allow us to form peer networks, and the entry and exit dates allow us to define a causal effect of interest. We conceptualize the causal role model effect as measuring the difference in the expected outcome of a resident (ego) who can observe one of their social contacts (e.g., peers who gave affirmations), to be successful in graduating before the ego's exit vs not successfully graduating before the ego's exit. Since peer influence is usually confounded with unobserved homophily in observational data, we model the network with a latent variable model to estimate homophily and include it in the outcome equation. We provide a theoretical guarantee that the bias of our peer influence estimator decreases with sample size. Our results indicate there is an effect of peers' graduation on the graduation of residents. The magnitude of peer influence differs based on gender, race, and the definition of the role model effect. A counterfactual exercise quantifies the potential benefits of intervention of assigning a buddy to "at-risk" individuals directly on the treated resident and indirectly on their peers through network propagation.

翻译：我们探讨治疗社区（Therapeutic Communities, TCs）中是否存在同伴影响或榜样效应，影响居民成功毕业。我们分析了来自三个治疗社区的匿名个体观测数据，这些社区记录了居民之间书面交流的肯定与纠正信息，以及他们精确的入院与出院日期。肯定性交流使我们能够构建同伴网络，而入院与出院日期则有助于定义我们感兴趣的因果效应。我们将因果榜样效应概念化为：测量一名居民（自我）在观察到其社交联系人（例如，给予肯定的同伴）在其退出前成功毕业相对于未在其退出前成功毕业时的预期结果差异。由于观测数据中同伴影响通常与未观测到的同质性混杂，我们采用潜在变量模型对网络进行建模以估计同质性，并将其纳入结果方程。我们从理论上保证，同伴影响估计量的偏差随样本量增大而减小。我们的结果表明，同伴的毕业对居民的毕业存在影响。同伴影响的强度因性别、种族以及榜样效应的定义而异。一项反事实分析量化了干预措施的潜在收益：为“高风险”个体分配伙伴，这将直接影响接受治疗的居民，并通过网络传播间接影响其同伴。