The objective of this study was to determine why the United States has experienced a higher rate of unemployment in the post-war period than other countries at similar stages of development. The study reviewed the Phillips Curve Theory--the theory underlying wage and price changes--and the development and post-war characteristics of labor market organizations and the industrial relations systems in the United States, Great Britain and Sweden. Aggregate wage and price change equations were estimated in each of the sample countries and the implied trade-offs between wage or price inflation and the unemployment rate were derived. The model developed was applied to data in order to estimate the coefficient in each country and observed international differences in turnover were explained. Two general policy measures, income policy and labor market policies, which have been widely applied during the period under study were assessed. (Author)