We present an agent-based model of weight choice and peer selection that simulates the effect of peer selection on social multipliers for weight loss interventions. The model generates social clustering around weight through two mechanisms: a causal link from others’ weight to an individual's...

Efforts to regionalize cardiac services can increase access costs for patients. This study is the first to quantify this trade off by estimating a demand model for surgery services that is used simulate the effect of centralization of cardiac services on hospital and treatment choices. The model...