Book excerpt: This chapter explores the origins of the theme of competitive advantage in 19th and early 20th century economics. This theme, which forms the core of modern Strategic Management, was a battleground for debates about the value of abstract theory versus observations about real-life events. Intellectual genealogies, citations, and other sources show the central roles played by the University of Vienna and Harvard University. These two institutions strongly influenced the theory of monopolistic competition as well as all three modern views of competitive advantage - the industrial as expressed by Porter, the resource-based as expressed by Penrose, and the evolutionary as expressed by Schumpeter.