The Discovery of the Isoquant

This article examines the first appearances of the isoquant, a concept that is central to production and supply theory. It appears to have been discovered independently by Bowley, Frisch, Cobb, and Lerner, in that order. Frisch coined the term isoquant. It is possible but not likely that Frisch took the concept from Bowley, and Lerner may have taken it from R. G. D. Allen. The article also discusses why the discovery of the isoquant was not made until more than forty years after that of the indifference curve, when to a modern analyst the isoquant appears isomorphic to the indifference curve and could have been copied straight from utility theory.