Are Public and Private Enforcement Complements or Substitutes? Evidence from High Frequency NHL Data

Abstract

A substantial theoretical literature identifies two general approaches to deterring anti-social behavior: public police actions (specialized enforcement) to monitor and punish proscribed behavior, and private actions (community enforcement) to discourage both illegal and legal, anti-social activity. Recent papers highlight the importance of both enforcement approaches but empirical identification of their relative effects has been challenging. Utilizing a novel, event-level database from the National Hockey League and random variation in the amount of rest between games that a referee oversees as an instrument, we find that the timing of events is crucial in determining the relationship between different enforcement actions. When specialized enforcement is lacking, community enforcement acts as an effective substitute for specialized enforcement. However, when specialized enforcers are present, community enforcement creates no further deterrence. Conversely, conditional on initial actions by community enforcers, specialized enforcement is an effective complement to community enforcement.