Risk, Uncertainty, and Profit

FRANK H. KNIGHT (1885-1972) is considered by some the greatest American scholar of economics of the 20th century. An economics professor at the University of Chicago from 1927 until 1955, he was one of the founders of the Chicago school of economics, which influenced Milton Friedman and George Stigler.
Here, his famous dissertation "Risk, Uncertainty and Profit" (1921) remains one of the most interesting reads in economics even today. In it, Knight made his famous distinction between "risk" (randomness with knowable probabilities) and "uncertainty" (randomness with unknowable probabilities), set forth the role of the entrepreneur in a distinctive theory of profit and gave one of the earliest presentations of the now-famous law of variable proportions in the theory of production.