Colin Clark, 1905–89, British economist. A statistics professor at Cambridge (1931–37), he taught in Australia and Great Britain until 1952, serving as economic adviser to the governments of both nations. Widely noted for his groundbreaking work in economic statistics and national income estimates, Clark was also among the first economists to use gross national product rather than national income as the basis of his studies. His best known work is The Conditions of Economic Progress (1940, repr. 1982).