The share of stocks beneficially owned by institutional investors has increased substantially over the last three decades. Together with a high and increasing level of concentration in the asset management industry, this trend implies that a small number of institutional investors now constitute...

We document substantial time-series and cross-sectional variation in branch-level deposit account interest rates, maintenance fees, and fee thresholds, and examine whether variation in bank concentration helps explain variation in these prices. HHI alone is not correlated with any of the outcome...

Many natural competitors are jointly held by a small set of large institutional investors. In the US airline industry, taking common ownership into account implies increases in market concentration that are 10 times larger than what is “presumed likely to enhance market power” by antitrust...

Scholars and antitrust enforcers have raised concerns about anticompetitive effects that may arise when institutional investors hold substantial stakes in competing firms. Their concern rests on empirical evidence that such common concentrated ownership is associated with higher prices and lower...

Some scholars have argued that the phenomenon known as common ownership, which refers to an investor's simultaneous ownership of small stockholdings in several competing companies, is anticompetitive and prohibited by the U.S. antitrust laws. These proponents target in particular large...

We use data from the U.S. airline industry to test the hypothesis, consistent with the general equilibrium oligopoly model of Azar and Vives (forthcoming), that inter-industry common ownership should be associated with lower prices in product markets. We find that, as the model predicts,...

Partial ownership of stock in multiple competing firms is an important scholarly and policy topic in both corporate and antitrust law. Until now, the discussion has focused on ownership. This essay shifts the debate from a focus on common ownership to a focus on common control. No prior work has...

Minority shareholdings have been on the regulatory agenda of competition authorities for some time. Recent empirical studies, however, draw attention to a new, thought provoking theory of harm: common ownership by institutional investors holding small, parallel equity positions in several...

A phenomenon known as “Common Ownership” arises when shareholders hold substantial stakes in competing firms. Although recent empirical evidence has illustrated how common concentrated owners are associated with higher product market prices and lower output, scholars remain divided as to the...

Horizontal shareholding exists when significant shareholders have stock in horizontal competitors. (It is often imprecisely called "common shareholding," but that term can also apply when shareholders own stock in two noncompeting corporations. It differs from "cross-shareholding," which...