Russian-born American economist and statistician who won the 1971 Nobel Prize for Economics.

Kuznets immigrated to the United States in 1922, 15 years after the arrival there of his father (who changed the family name to Smith, though the young Kuznets preferred the original name). He was educated at Columbia University, receiving his Ph.D. in 1926. In 1927 he joined the National Bureau of Economic Research, working with its founder, Wesley Mitchell (Mitchell, Wesley C.). It was there that Kuznets developed his pioneering studies of U.S. national income (national income accounting) and his more general work on economic time series, resulting in comprehensive studies of the economic growth of nations. His study of American national income began with statistics from 1869, encompassing a long-term approach that had never been attempted. Out of this work came an understanding of how to measure gross national product (GNP). Kuznets's research set high standards for all similar studies that would follow. After his work with the federal government, Kuznets taught at the University of Pennsylvania (1930–54), Johns Hopkins University (1954–60), and Harvard University (1960–71).

In all his research, Kuznets emphasized the complexity of fundamental economic data by stressing that reliable results can be derived only through large numbers of observations. Likewise, he criticized the limitations inherent in simple economic models based, for example, on one phase of historical experience. Kuznets insisted that economic data must include information on population structure, technology (technology, history of), the quality of labour, government structure, trade, and markets in order to provide an accurate model. He broke convention by emphasizing, on the basis of the statistical series that he accumulated, how little of economic growth could actually be attributed to the accumulation of labour and capital. He also identified cyclic variations in growth rates (now called “Kuznets cycles”) and linked them with underlying factors such as population.

Kuznets received the Nobel Prize for empirical work that led him to identify the nexus of modern economic development. According to Kuznets, the epoch of “modern economic growth” began in northwestern Europe in the last half of the 18th century and later spread south and east, reaching Russia and Japan by the end of the 19th century. Through this study Kuznets determined that per capita income rose by 15 percent or more each decade, which had been unheard of in precapitalist societies.