In February 1999 the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan added this study to its archive. Cross-National Indicators Of Liberal Democracy, 1950-1990, is an international collection of political, social, and economic measures, containing more than 800 variables, for most of the world's independent countries. Topics covered by the study include "adult suffrage; civil liberties; political rights; the openness, fairness, and competitiveness of the electoral process; executive and legislative selection and effectiveness; political party legitimacy; political participation; limitations on the executive branch of the government; level of democratization; economic openness; constitutional development; government legitimacy; and the outlook for freedom." The ICPSR freely provides a codebook and documentation in compressed and uncompressed .pdf format. The data set is provided in a compressed and uncompressed SAS transport file, and may be downloaded by authorized member institutions and official representatives of the ICPSR Data Archive. Downloading specifications and instructions are provided.