In the seven chapters presented here noted economist and Nobel Prize–winner Simon Kuznets summarizes the results of his studies of the economic growth of nations in modern times. Working over the last twenty years, he has concerned himself largely with national product and its components—with long-term trends in growth in total output and in labor force changes in production structure. Such comprehensive data, Kuznets maintains, in which significantly different elements are distinguished and measured, are indispensable both for observations and analysis of the essentially quantitative process of economic growth and for the search for the general and variant characteristics of this growth. He covers a variety of countries and is able to suggest valid general characteristics and test the limits within which they hold. He also provides comparisons between the economically developed and the less developed countries and evaluates the relation between per capita product and the structure of production and the movements of both over time in the course of modern economic growth.