The Theory of the Leisure Class: An Economic Study of Institutions (1899), by Thorstein Veblen, is a treatise of economics and sociology, and a critique of conspicuous consumption as a function of social class and of consumerism, which are social activities derived from the social stratification of people and the division of labor; the social institutions of the feudal period that have continued to the modern era.

Thorstein Bunde Veblen was an American economist and sociologist who, during his lifetime, emerged as a well-known critic of capitalism.