Facebook, Amazon, Netflix and Google, as well as Twitter – the FANG companies – have transformed society with both positive and negative effects. Soaring consumer access to information, news, social networks, and entertainment has been stimulated by the ever-more ubiquitous and falling...

There can be no doubt that the FANG companies – Facebook, Amazon, Netflix and Google, as well as Twitter – have transformed society since their emergence. Like all social transformations, the changes wrought by their services have had ripple effects that are both positive and negative. On...

When regulated markets are liberalized, economists always stress the benefits of fragmenting existing capacities among more firms. This is because oligopoly models typically imply that a larger number of firms generates stronger competition. I show in this paper that this intuition may fail...

By employing a dynamic model with two limit order books, we show that fragmentation is associated with reduced competition among liquidity suppliers and lower picking-off risk of limit orders. Due to these countervailing channels, the impact of fragmentation on liquidity and welfare differs with...

We study how monetary policy affects local market competition in a union of countries experiencing different economic conditions: the euro area. We find that when monetary conditions tighten (loosen), from the point of view of an individual economy, market concentration increases (declines)....

Extreme adverse selection arises when private information has unbounded support, and market breakdown occurs when no trade is the only equilibrium outcome. We study extreme adverse selection via the limit behavior of a financial market as the support of private information converges to an...