Diversification: Causes, Consequences, and Welfare Effects

DICACO analyses causes, consequences, and welfare effects of diversification, once equilibrium effects that affect investor welfare and side effects that affect consumers and taxpayers are considered. The analysis informs the question:Is cheap diversification good for society?Sub-projects investigate (i)Theory: whether benefits of diversification that accrue to individual investors viewed in isolation also benefit investors in equilibrium, once effects on asset prices are considered;(ii)Empirics: to which extent diversification motives drive “common ownership” of product market competitors; (iii)Theory and empirics: whether bidding behavior in government procurement auctions depends on whether bidders are owned by diversified investors, how much taxpayer money is inefficiently transferred to shareholders as a result, and how procurement auctions could be redesigned to re-claim efficiency losses caused by diversified ownership of bidders;(iv)Theory: how predictions on portfolio choice, equilibrium ownership, asset prices, firm behavior, and product prices depend on jointly endogenizing all these variables, and how this equilibrium depends on the implementation of policy proposals that seek to restrict investor diversification.We use tools from general equilibrium theory and numerical computer simulations in (i) & (iv); machine learning and reduced-form econometrics in (ii); auction theory and structural estimation in (iii).The project develops new methods to solve equilibrium asset pricing models and for auction theory. The uniquely comprehensive dataset on corporate ownership will be open sourced for academic research worldwide. Because of the potential to shift beliefs, the provision of new tools for academic research, and because policy makers might erase trillions of Euros of economic gains by enacting the wrong policies, overall, the risks of the project are justified by the high gains for both researchers and policymakers.