Industrial relations Labor economics Economics Labor and laboring classes Macroeconomics I.Title Microeconomics Comparative economics Economic conditions Economic history Wages Agriculture Agriculture and state Bibliography Congresses Directories Ecnomic development Economic aspects History I.Gregory, Peter, joint auth II.Title (Series: Yale Univ. Economic Growth Center. Publications) Labor and laboring classes--Puerto Rico Labor mobility Labor supply Labor supply--Puerto Rico Labor unions Migration, Internal Programmmed instruction Wages--Puerto Rico