How Much Do Strategic Groups Matter?

Understanding firm heterogeneity is the first step towards explaining the dispersion of profit rates between firms. This paper proposes a framework that distinguishes between three sources of competitiveness, related to three levels of firm heterogeneity, which give rise to industry competencies, strategy-specific competencies and firm-specific competencies. Using data from a Spanish survey we estimate the relative importance of these three sources of heterogeneity. We show that taking the group effect into account significantly differentiates our results from those obtained in previous research. We provide new evidence on the existence of a significant group effect and also an estimate of its relative importance vis á vis firm and industry effects.