He played a role in shaping the Chicago tradition in price theory, which began with Frank Knight and Jacob Viner in the 1920s and 1930s.

This tradition has been spread globally by numerous students and scholars, including Friedman himself, as well as other notable economists from Chicago such as George Stigler, Gary Becker, and Ronald Coase.

[1] Friedman's book Price Theory: A Provisional Text, originally based on lecture notes taken by David I. Fand and Warren J. Gustus in 1951–52.

[1] Friedman's approach to price theory emphasized the insights of Alfred Marshall, combining theoretical analysis with real-world applications.

This approach, characterized by its simplicity compared to more mathematically complex theories, offered a powerful tool for addressing a wide range of economic problems.