---- Acknowledgements ----
Special thanks go to Daniel Green and Hoai-Luu Nguyen for outstanding research assistance. The authors also thank Paolo Angelini, Gadi Barlevy, René Carmona, Stephen Brown, Robert Engle, Mark Flannery, Xavier Gabaix, Paul Glasserman, Beverly Hirtle, Jon Danielson, John Kambhu, Arvind Krishnamurthy, Burton Malkiel, Maureen O'Hara, Andrew Patton, Matt Pritsker, Matt Richardson, Jean-Charles Rochet, José Scheinkman, Jeremy Stein, Kevin Stiroh, René Stulz, and Skander Van den Heuvel for feedback, as well as seminar participants at numerous universities, central banks, and conferences. We are grateful for support from the Institute for Quantitative Investment Research Europe. Brunnermeier also acknowledges financial support from the Alfred P. Sloan Foundation. The views expressed in this paper are those of the authors and do not necessarily represent those of the Federal Reserve Bank of New York, the Federal Reserve System, or the National Bureau of Economic Research.