Deadweight Loss

French engineer-economist Jules Dupuit first described the concept in 1844 while analyzing the optimal toll for a bridge, identifying what he called "lost utility" — surplus destroyed when potential users were priced out. Alfred Marshall later formalized the consumer surplus framework Dupuit had pioneered. The modern term "deadweight loss" and its triangular graphical representation were cemented by Arnold Harberger in his landmark 1954 paper on monopoly and resource allocation, after which such efficiency-loss areas became known as Harberger triangles.