We propose a new welfare criterion that allows us to rank alternative financial market structures in the presence of belief heterogeneity. We analyze economies with complete and incomplete financial markets and/or restricted trading possibilities in the form of borrowing limits or transaction...

The ‘flash crash' of May 6th 2010 was the second largest point swing (1,010.14 points) and the biggest one-day point decline (998.5 points) in the history of the Dow Jones Industrial Average. For a few minutes, $1 trillion in market value vanished. In this paper, we argue that the ‘flash...

Recently exchanges have been directly selling market data. We analyze how this practice affects price discovery, the cost of capital, return volatility, and market liquidity. We show that selling price data increases the cost of capital and volatility, worsens market efficiency and liquidity,...