Abstract
This article supplies a missing piece in the story of the growth of managerial technology—the development of discounted cash flow techniques for projecting the profitability of capital budgeting alternatives. The article traces the origins of these methods in the industrial sector to the early work of railroad locating engineers and describes the refinement of DCF practices by AT&T and chemical firms. It concludes with a discussion of the diffusion of this analytic tool through the interaction of practicing engineers, consultants, professional associations, and scholarly publications.