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Impact Assessment of Arizona's Lowered Legal Drinking Age and a Review of the Previous Research

NCJ Number
Date Published
December 1983
An interrupted time-series analysis of selected data indicates that Arizona's lowering of the legal drinking age from 21 to 19 years old in 1972 resulted in a significant immediate and sustained increase in fatal traffic crashes and crash-related deaths as well as an increase in alcoholic beverage consumption.

Based on a review of previous research, the study hypothesized that the lowering of the minimum drinking age in Arizona would increase fatal traffic accidents, crash-related deaths, and alcoholic beverage consumption among law-affected youth. The statistical technique used in the study was interrupted time-series analysis, which involves the measurement of a variable over time to determine any changes of pattern due to an event which 'interrupts' the normal process of the time series. The variables measured for the years 1960-1981 were fatal crashes; crash-related deaths; and beer, wine, and liquor sales. The intervention point analyzed was the implementation date of the 1972 drinking-age law. The law produced a 23-percent increase in beer sales, a 26-percent increase in fatal crashes, and a 36-percent increase in traffic deaths. The 21-year-old minimum drinking age should be reinstated. 11 tables, 22 figures, and 74 notes.

Date Published: December 1, 1983