title: Do alcohol compliance checks decrease underage sales at neighboring establishments?
abstract: OBJECTIVE
  Underage alcohol compliance checks conducted by law enforcement agencies can reduce the likelihood of illegal alcohol sales at checked alcohol establishments, and theory suggests that an alcohol establishment that is checked may warn nearby establishments that compliance checks are being conducted in the area. In this study, we examined whether the effects of compliance checks diffuse to neighboring establishments.
  
  
  METHODS
  We used data from the Complying with the Minimum Drinking Age trial, which included more than 2,000 compliance checks conducted at more than 900 alcohol establishments. The primary outcome was the sale of alcohol to a pseudo-underage buyer without the need for age identification. A multilevel logistic regression was used to model the effect of a compliance check at each establishment as well as the effect of compliance checks at neighboring establishments within 500 m (stratified into four equal-radius concentric rings), after buyer, license, establishment, and community-level variables were controlled for.
  
  
  RESULTS
  We observed a decrease in the likelihood of establishments selling alcohol to underage youth after they had been checked by law enforcement, but these effects quickly decayed over time. Establishments that had a close neighbor (within 125 m) checked in the past 90 days were also less likely to sell alcohol to young-appearing buyers. The spatial effect of compliance checks on other establishments decayed rapidly with increasing distance.
  
  
  CONCLUSIONS
  Results confirm the hypothesis that the effects of police compliance checks do spill over to neighboring establishments. These findings have implications for the development of an optimal schedule of police compliance checks.
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Darin J
authors.initials: DJ
authors.lastname: Erickson
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Smolenski
authors.forename: Traci L
authors.initials: TL
authors.lastname: Toomey
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Carlin
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Wagenaar
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology / Q000331:legislation & jurisprudence*; D000434:Alcoholic Beverages / Q000191:economics / Q000600:supply & distribution*; D003132:Commerce / Q000331:legislation & jurisprudence*; D006801:Humans; D035846:Law Enforcement / Q000379:methods*; D016013:Likelihood Functions; D016015:Logistic Models; D008297:Male; D016495:Police; D012111:Residence Characteristics; D013997:Time Factors; D055815:Young Adult