Introduction

Abstract

Industrial Organization is one of the economic fields most subjected to the torrents of professional and methodological modes. The origins of IO have been marked by the conflict between the deductive and the inductive approaches. During the 1950s and 1960s, empirical research was dominant; the hypotheses under investigation were derived in a rather loose way from microeconomic theory, or from casual or even anecdotical evidence. If a theory existed, it was the socalled StructureConduct-Performance Paradigma, which suggested in its purest form that structure determines conduct, which itself determines performance.