Abstract ：
The purpose of this study is to examine the early development of opportunity cost in the English-speaking world during the late 19th and early 20th centuries and draw a pre-history of opportunity cost theory in the Chicago and LSE schools. In previous studies, the opportunity cost concept was regarded as a subjective cost derived from Austrian schools. However, the opportunity cost concept did not develop directly from the subjectivist theories of the Austrian school but rather underwent a unique transition in the English-speaking world. Therefore, until the early 20th century, the opportunity cost debate did not place as much importance on Buchanan's two types of subjectivism and objectivism as it does today. Davenport and Wicksteed considered opportunity cost from both subjectivist and objectivist perspectives and examined cost not only from the demand side but also from the supply side. It provides a new perspective that the pre-history of opportunity cost of the Chicago and LSE schools should be understood by the dichotomy, which is not the division between subjectivism and objectivism but demand and supply, or individuals and society.

JEL classification: B12, B13, D46

Keywords: opportunity cost, history of modern economics, the LSE, the Chicago school, H. J. Davenport, P. H. Wicksteed, J. M. Buchanan