The less developed countries (LDC) present two kinds of challenge to economists. First, they invite us to develop hypotheses about how economic growth begins and about structural changes during the early decades of growth. Second, they provide a fresh terrain on which specialists in particular subject-matter areas can test accepted notions about economic behaviour. For investigations in labour economics, the structure of earnings provides a convenient starting point. (It is best to say “earnings” rather than “wages” because most workers in the LDC’s are self-emplqyed.) Analysis of earnings requires an examination of manpower supplies and requirements. This leads into the economics of agriculture, industry, government, and other labour demanding sectors on one side, and into a study of education and other skill-producing agencies, on the other. Thus by starting with the earnings structure, one is led rather directly into the heart of the economy.