Two forces have reshaped global securities markets in the last decade: Exchanges operate at much faster speeds and the trading landscape has become more fragmented. In order to analyze the positive and normative implications of these evolutions, we study a framework that captures (i) exchanges'...

The financial crisis has demonstrated the need to better analyze financial innovations. While some of these innovations are beneficial, others do not improve overall welfare and create unacceptable risks for the economy. A major impediment to efficient regulation is the lack of research...