title: Permission to cross the border: effective policy reduces high-risk drinking by Marines.
abstract: OBJECTIVE
  At a Marine Corps base near the Mexican border, off-base alcohol- related incidents increased when serving alcohol to personnel under age 21 on the base was no longer permitted. The bars across the Mexican border, where the legal drinking age is 18, are an important source of alcohol for the Marine enlisted men. To reduce cross-border drinking, the base command instituted a "chit" system requiring enlisted men to receive written permission to cross the border. This study evaluates the effectiveness of that policy.
  
  
  METHODS
  Breath test surveys of American youths returning from Tijuana to San Diego County provided counts and blood alcohol concentration (BAC) of marines returning from a night of drinking in Mexico before and after the "chit" policy. Comparison counts and breath tests for Navy personnel from a San Diego base not affected by the "chit" policy were available for the same time periods.
  
  
  RESULTS
  The number of underage marines returning from Mexican bars was reduced by 78%, and of those the number with illegal (> or = .08%) BACs was reduced by 84%. There was no significant change for the comparison group of sailors.
  
  
  CONCLUSIONS
  It appears that the "chit" policy was highly effective at least for the 6-month post-period covered by this study. This apparent success influenced the implementation of the "chit" policy on all naval facilities in the San Diego area.
authors.affiliation: Pacific Institute for Research and Evaluation, 11710 Beltsville Drive, Suite 300, Calverton, Maryland 20705, USA. voas@pire.org
authors.forename: Robert B
authors.initials: RB
authors.lastname: Voas
authors.forename: Mark
authors.initials: M
authors.lastname: Johnson
authors.forename: James
authors.initials: J
authors.lastname: Lange
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000517:prevention & control* / Q000523:psychology; D001944:Breath Tests / Q000379:methods; D016009:Chi-Square Distribution; D006801:Humans; D008800:Mexico; D008889:Military Personnel / Q000523:psychology / Q000706:statistics & numerical data*; D011640:Public Policy; D012309:Risk-Taking; D014481:United States