Washington Law Review Volume 95 Number 1 3-2020 Externalities and the Common Owner Madison Condon New York University School of Law,
[email protected] Follow this and additional works at: https://digitalcommons.law.uw.edu/wlr Part of the Antitrust and Trade Regulation Commons, and the Business Organizations Law Commons Recommended Citation Madison Condon, Externalities and the Common Owner, 95 Wash. L. Rev. 1 (2020). Available at: https://digitalcommons.law.uw.edu/wlr/vol95/iss1/4 This Article is brought to you for free and open access by the Law Reviews and Journals at UW Law Digital Commons. It has been accepted for inclusion in Washington Law Review by an authorized editor of UW Law Digital Commons. For more information, please contact
[email protected]. 04 Condon.docx (Do Not Delete) 4/28/20 6:39 PM EXTERNALITIES AND THE COMMON OWNER Madison Condon* Abstract: Due to the embrace of modern portfolio theory, most of the stock market is controlled by institutional investors holding broadly diversified economy-mirroring portfolios. Recent scholarship has revealed the anti-competitive incentives that arise when a firm’s largest shareholders own similarly sized stakes in the firm’s industry competitors. This Article expands the consideration of the effects of common ownership from the industry level to the market portfolio level and argues that diversified investors should rationally be motivated to internalize intra-portfolio negative externalities. This portfolio perspective can explain the increasing climate change related activism of institutional investors, who have applied coordinated shareholder power to pressure fossil fuel producers into substantially reducing greenhouse gas emissions.