Economic development is the increase in the amount of people in a nation's population with sustained growth from a simple, low-income economy to a modern, high-income economy. Its scope includes the process and policies by which a nation improves the economic, political, and social well-being of its people. "'Economic development' or 'development' is a term that economists, politicians, and others have used frequently in the 20th century. The concept, however, has been in existence in the West for centuries. Modernization, Westernization, and especially Industrialization are other terms people have used when discussing economic development. Although no one is sure when the concept originated, most people agree that development is closely bound up with the evolution of capitalism and the demise of feudalism." The study of economic development by social scientists encompasses theories of the causes of industrial-economic modernization, plus organizational and related aspects of enterprise development in modern societies. It embraces sociological research on business organization and enterprise development from a historical and comparative perspective; specific processes of the evolution (growth, modernization) of markets and management-employee relations; and culturally related cross-national similarities and differences in patterns of industrial organization in contemporary Western societies. On the subject of the nature and causes of the considerable variations that exist in levels of industrial-economic growth and performance internationally, it seeks answers to such questions as: "Why are levels of direct foreign investment and labour productivity significantly higher in some countries than in others?"