Issues in the Comparative Measurement of Political Democracy

The empirical study of the causes and consequences of political democracy has been the subject of considerable research. Yet cumulative development of this research is hampered by the controversial aspects and limitations of the existing indices of political democracy. These issues concern the validity of the indicators, the unknown reliability, and the limited sample and temporal coverage of these indices. After a discussion of these issues, a revised index of political democracy that overcomes some of these limitations is presented. The indicators of the revised index are analyzed by means of confirmatory factor analysis and the reliability of the measure is discussed. The index is generally better than existing measures in reliability, sample size, and temporal coverage; but the remaining limitations of the index are reviewed. The moderate to high correlations of this index with other democracy indices support its external validity. Yet, the differences in empirical results possible by using different indices are demonstrated. Finally, there are two appendices. The first provides the technical details of the confirmatory factor analysis. The second appendix lists the values of the political democracy index.