Joe Bain, a pioneer of Industrial Economics, was born hundred years ago. Bain defined the “Structure-conduct-performance” (SCP) paradigm which represented for years the pillar of the discipline and which remains today, with a few revisions, rich of potential development. Bain is particularly famous for his studies on oligopoly and entry barriers, on which Paolo Sylos Labini also has seminal contributions. The studies of both scholars constituted the basis for a wide theoretical reflection with important applications, so much so that Franco Modigliani, when presenting both authors’ work in 1958, talked about a new frontier for research on oligopoly. It is also useful to examine how Bain came to define the SCP paradigm, in order to appropriately derive both the essential characteristics and the development of the discipline, which in Italy is called Industrial Economics and Policy.