This book is the first major study of the life and work of Allyn Young. It is an intellectual biography of one of the most prominent and influential economists of the interwar period.

The book details Allyn Young's remarkedly varied academic career during which he held posts in seven American universities and one in Britain. He was an inspiring and admired teacher, particularly in graduate work, as attested to by former students: Frank Knight, Edward Chamberlin, Bertil Ohlin, Eleanor Dulles, Nicholas Kaldor and others.

Young's equally varied professional publications, ranging from his early papers on demographics to his final insights on increasing returns, are discussed, along with expositions of his ideas on value theory, depreciation, taxation, index number theory, and the antitrust statutes. He never wrote a treatise but was writing one on monetary theory at the time of his death.

He performed extensive public service during his lifetime. A full account of his work as economic adviser to the American delegation at the Paris Peace Conference, his postwar controversy with J. M. Keynes, and his service as a consultant to the League of Nations are presented in the book.