The three treatises in On the Manipulation of Money and Credit were written in German between 1923 and 1931. Together they include some of Mises's most important contributions to monetary and trade-cycle theories and constitute a precursor to Mises's major work, Human Action. Ludwig von Mises (1881-1973) was the leading spokesman of the Austrian School of economics throughout most of the twentieth century. Bettina Bien Greaves is a former resident scholar and trustee of the Foundation for Economic Education and was a senior staff member at FEE from 1951 to 1999.