Fields of academic inquiry differ in their preferred forms of output, in the ways in which knowledge is accumulated and stored, and so in the ways that academic influence is measured. We compare Tom Hertel’s research record to other international economists of his generation in order to illustrate the unique breadth and influence of his work, and of the GTAP project broadly. We then provide an analytical framework that helps explain the evolution of the field of international economics from a tool-use standpoint. This framework helps us to assess the academic productivity gains from creating the GTAP model and consortium. It also provides a possible answer to a significant puzzle: why is GTAP increasingly influential in the physical and biological sciences, but less so within the international economics community?