Social interest in problems such as domestic violence is typically motivated by concerns regarding equity, rather than efficiency. However, we document that taking steps to reduce domestic violence by reporting it yields substantial benefits to external parties. Specifically, we find that although children exposed to as-yet-unreported domestic violence reduce the achievement of their classroom peers, these costs disappear completely once the parent reports the violence to the court. This suggests that the public has an interest in helping families to overcome their problems in general and to report domestic violence in particular. It also suggests that social and judicial interventions may help combat negative peer effects in schools. (Contains 3 tables, 25 footnotes, and 1 figure.)