Clark, John Bates, 1847-1938, American economist, b. Providence, R.I. He studied economics in the U.S. and Germany, and taught at Columbia Univ. and several other colleges in the United States. In 1885 he helped found the American Economic Association, serving as its president (1893-95). Clark's best-known work, The Distribution of Wealth (1899), outlined his theory of marginal productivity, based on an ideal of competitive equilibrium without dynamic change. By the breadth of his work and contributions to economics, Clark became the first American economist to achieve international distinction.