The Affluent Society (1958), John Kenneth Galbraith's most broadly influential book, stands out among works of economic analysis for its accessible writing style, which makes complex economic concepts and arguments understandable to the popular reader. Galbraith's phrase "conventional wisdom," a key concept introduced in The Affluent Society, has entered common parlance so pervasively that it is now used to describe a variety of concepts not necessarily related to economic theory.

Galbraith asserts that the conventional wisdom of economic thinking in the United States is based in nineteenth-century European economic theory and is no longer suited to the unprecedented phenomenon of mass affluence achieved by American society in the twentieth century. He criticizes the overemphasis on high rates of production as a measure of economic prosperity, suggesting that other factors may be of greater importance. He further asserts that economic theory must take into account the importance of advertising in artificially creating high rates of consumption to support high rates of production.

Galbraith's central concerns in reassessing the American economy include: the nature of American affluence; the relationship between production, consumption, and advertising; the abiding issue of poverty and economic inequality; and changing factors in such economic concerns as employment, inflation, and consumer debt. He ultimately advocates a greater emphasis on sales tax over property tax; greater government expenditure on such public services as education and health care; and a national goal of expanding the "new class" of citizens able to pursue work they find inherently enjoyable.