Mises presents and discusses all existing economic theories and then proceeds to explain how the only sensible, realistic, and feasible theory of economics is one based on how the needs and desires of human beings dictate trends, affect profits and losses, adjust supply and demand, set prices, and otherwise maintain, regulate, and control economic forces. (1881–1973) was the leading spokesman of the Austrian School of economics throughout most of the twentieth century. 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.