"Presents a unique view of social problems and conflicts over urban space from the cab of an ambulance.While we imagine ambulances as a site for critical care, the reality is far more complicated. Social problems, like homelessness, substance abuse, and the health consequences of poverty, are...

We employ a standard identification strategy from the peer effects literature to investigate the importance of network definitions in estimation of endogenous peer effects. We use detailed information on friends in the Adolescent Longitudinal Health Survey (Add Health) to construct two network...