Arten und Ursachen der Arbeitslosigkeit in ihrer Bedeutung für die Beschäftigungspolitik

1. Economists have to distinguish between different kinds and different causes of unemployment. 2. The same kind of unemployment can have different causes and the same cause can provoke several kinds of unemployment. 3. The analysis of equilibrium (and "disequilibrium") is alone not sufficient to explain all kinds of unemployment because unemployment in market economies is usually based on the development of supply and demand. 4. The subjekt of unemployment theory cannot be restricted to the analysis of equilibrium (or "disequilibrium") but has to include the economic effects of investment for rationalization as well as of investment for innovation of new and better consumer goods and therewith of "progress and development" (A. Marshall)