Spillover Effects in Health Service Use: Evidence From Mental Health Care Using First‐Year College Housing Assignments

Spillover effects in health service use may represent an important externality of individual treatment decisions and are important for understanding the consequences of interventions to improve access to health care. This study is the first to our knowledge to examine causal spillover effects for mental health service use. We exploit the natural experiment of first-year student housing assignments at two universities using survey data that we collected. When the peer group is defined at the roommate level, we do not find any spillover effects on service use. When the peer group is defined at the hall level, we find positive spillover effects--peers' service use increases one's own service use--and this effect is driven by individuals with prior experience with mental health services. We also find some evidence that the mechanism behind this effect is improved beliefs about treatment effectiveness.