CORPORATE OWNERSHIP DATA

Our aim is to provide accessible data on who holds the shares and votes in U.S. public firms... To analyse and understand the effects of shareholder and control structures in U.S. publicly traded corporations, we require accurate data on the holdings of active and passive institutional and individual investors, and corporate insiders, such as CEOs and board members. For the past decades we either collected this data individually for a limited subset of firms, or relied on very expensive and often incomplete sources of ownership data, such as Thomson Reuters 13-F data, Factset or CapitalIQ. This is insufficient if we want to properly assess the trends in corporate ownership structures and evaluate their effects on corporate outcomes, competition and market outcomes. For the benefit of the profession we are making a new and complete data set of control and shareholdings in all U.S publicly traded corporations freely available.