Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This study evaluates the effects of institutional investors' common ownership of firms competing in the same market. Overall, common ownership has two opposing effects: (a) it serves as a device for weakening market competition, and (b) it induces diversification, thereby reducing portfolio risk. We conduct a detailed welfare analysis within which the competition‐softening effects of an increased degree of common ownership is weighted against the associated diversification benefits.