Designed to assess the impact of the State's purchase age legislation prohibiting the dispensing of alcohol to anyone under 21, the surveys included 2,000 subjects each in the first 2 samples, and 3,000 each in the latter 2. The percentage of respondents who had purchased alcohol in the previous 28 days showed significant reductions in the age groups affected by legislative changes (all over 50 percent), while the rates of purchase by those not affected (21- to 24-year-olds) showed modest increases. Similar decreases were found in alcohol consumption, with 19-year-olds showing a 17.5-percent decrease and 20-year-olds showing a 25.25-percent decrease by 1986. After the drinking age was raised to 21, intoxication rates (defined as having five or more drinks on a single occasion) showed a 33.98-percent and a 31.84-percent decrease among 18- and 19-year-olds, respectively. Results show that the legal minimum purchase age legislation has had a direct impact on alcohol purchase and consumption. 5 tables and figures.