- A leading academic socialist in the Weimar Republic. Emigrated to the United States of America in early 1930s where he continued to work on problems of business cycles and technological unemployment at the New School with Adolph Lowe and Hans Neisser. Professor, New School Social Research, New York City, United States of America, 1933-1939.
- Die wirtschaftlichen Organisationen. (German Edition)
- This is a reproduction of a book published before 1923.