title: The age-21 minimum legal drinking age: a case study linking past and current debates.
abstract: BACKGROUND
  The minimum legal drinking age (MLDA) in the United States (U.S.) has raised debate over the past several decades. During the 1970s many states lowered their MLDAs from age 21 to 18, 19, or 20. However, as a result of studies showing that these lower MLDAs were associated with increases in traffic crashes, state-level movements began in the later1970s to return MLDAs to age 21. A new movement has arisen to again lower the MLDA in the U.S. Aim The aim is to discuss this current MLDA debate within the context of the long history of the U.S. MLDA.
  
  
  METHODS
  A search of research articles, websites, and newspaper articles was conducted to identify key messages and influences related to the MLDA movements.
  
  
  RESULTS
  The complexity of state movements to change their MLDAs is illustrated by the Michigan experience, where strong political forces on both sides of the issue were involved, resulting in the MLDA returning to 21. Because the 21st Constitutional amendment prevents the federal government from mandating a MLDA for all states, a federal policy was proposed to provide incentives for all states to implement age-21 MLDAs. Due largely to strong research evidence, the National Minimum Legal Drinking Age Act was enacted in 1984, stipulating that states set their MLDA to 21 or face loss of federal highway funds. By 1988, all states had an age-21 MLDA.
  
  
  CONCLUSIONS
  Any current debate about the MLDA should be informed by the historical context of this policy and the available research.
authors.affiliation: The University of Minnesota, School of Public Health, Division of Epidemiology and Community Health, Minneapolis, MN 55454, USA. toome001@umn.edu
authors.forename: Traci L
authors.initials: TL
authors.lastname: Toomey
authors.forename: Toben F
authors.initials: TF
authors.lastname: Nelson
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Lenk
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000331:legislation & jurisprudence* / Q000639:trends; D003431:Cross-Cultural Comparison; D006801:Humans; D008824:Michigan; D014481:United States; D055815:Young Adult