1. Department of Information, Operations, and Management Science, New York University Stern School of Business, New York, New York 10012
2. Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
3. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
4. Department of Computer Science and Engineering, University of Washington, Seattle, Washington 98105
5. Department of Management Science and Engineering, Stanford University, Stanford, California 94305