A Meta-Analytic Review of the Concentra tion-Performance Relationship: Aggregating Findings in Strategic Management

This paper investigates the central methodological and substantive controversies surrounding the relationship between concentration and performance which lies at the heart of many strategy content models. We introduce the technique of meta-analysis to evaluate the nature of the relationship and to empirically assess the controversies using existing data. Our findings suggest that the relationship is moderated by industry definition and time period of data and is not affected by methodological artifacts. The implications of the findings are discussed with particular reference to the problems of aggregation that are likely to confront strategic management researchers in the future.