OWNERSHIP VERSUS TIMING OF THE GAME

This study examines the impact of timing of the game on the welfare gains of privatisation in the presence of strategic trade policy. We argue that only if the public enterprise acts as a Cournot player will it generate an additional distortion that could outweigh the distortion caused by the oligopolistic behaviour of private firms. But with a first-mover advantage it can serve as an effective regulatory device comparable with a production subsidy. We further show that, in the presence of strategic trade policy, Cournot assumptions are inconsistent with the firms' preferences over the timing of the game. As public Stackelberg leadership is a subgame Nash equilibrium of the extended game with endogenous order of moves, we conclude that it is the timing of the game rather than firms' ownership structure which is responsible for the inefficiency of an international mixed market found by earlier studies.     

The Flash Crash: High‐Frequency Trading in an Electronic Market

We study intraday market intermediation in an electronic market before and during a period of large and temporary selling pressure. On May 6, 2010, U.S. financial markets experienced a systemic intraday event—the Flash Crash—where a large automated selling program was rapidly executed in the E‐mini S&P 500 stock index futures market. Using audit trail transaction‐level data for the E‐mini on May 6 and the previous three days, we find that the trading pattern of the most active nondesignated intraday intermediaries (classified as High‐Frequency Traders) did not change when prices fell during the Flash Crash.     

Reusing Natural Experiments

After a natural experiment is first used, other researchers often reuse the setting, examining different outcome variables. We use simulations based on real data to illustrate the multiple hypothesis testing problem that arises when researchers reuse natural experiments. We then provide guidance for future inference based on popular empirical settings including difference-in-differences, instrumental variables, and regression discontinuity designs. When we apply our guidance to two extensively studied natural experiments, business combination laws and the Regulation SHO pilot, we find that many results that were statistically significant using single hypothesis testing do not survive corrections for multiple hypothesis testing.