High and persistent unemployment has been experienced by most developed countries during the 1980s. Many researchers have sought to explain this development in terms of "mismatch," arguing that the economies that have suffered most from persistently high unemployment are those that have been least flexible in matching their unemployed with the available employment opportunities. This conference proceedings volume examines the evidence on sectoral wage differentials, labor mobility and the ratio of unemployment to job vacancies in detailed studies of seven countries with a wide variety of labor market and macroeconomic structures: the United States, Japan, West Germany, Sweden, the United Kingdom, Italy and Spain.