Objective: An unprecedented change in Iowa's Alcoholic Beverage Control (ABC) Laws provides a unique opportunity to learn more about the affects of these laws and the interrelationship of alcohol availability, consumption and problems. A better understanding of these relationships is essential to developing more informed and effective alcoholism prevention and treatment strategies. Aim: To test the distribution of consumption prevention model prediction that increased alcohol availability increases consumption and problem drinking. The specific hypotheses to be tested are that Iowa's substantial increase in spirits availability led to: A) increased spirits consumption, B) increased total alcohol consumption, C) increased heavy drinker rates, and D) increased problem drinker rates. Additionally, the study will investigate how the interrelationship of alcohol availability, consumption and problems may be affected by sociodemographic variables, drinking contexts and drinking patterns. Methods: A before/after time series trend analysis will be made of changes in official alcohol sales figures, fatal auto accidents and alcohol-related fatal auto accidents in Iowa and in nearby comparison states that did not experience the same major ABC Law and alcohol availability change as Iowa. Before/after survey data from Iowa and nearby comparison states will be used to supplement and cross validate the time series analysis. The survey data will and measures of heavy drinking rates, several specific problem drinking indicators, drinking contexts, drinking patterns and sociodemographics to the analysis. Also, self-reported consumption and drunk driving will be used to cross validate the time series findings which the surrogate measures of these variables - sales and traffic accident records. This triangulation of data from official records and survey self- reports would be the most comprehensive investigation of the consequences of an unprecedented ABC Law change and the most definitive test of the single distribution prevention model hypotheses to date.