This three-volume work is composed of essays written by many of Kenneth Arrow's students and collaborators. Although it is impossible to cover the entire range of his contributions to economics, we have organized the presentation around the major topics of his research career: Volume I treats “Social Choice and Public Decision Making,” Volume II covers “Equilibrium Analysis,” and Volume III deals with “Uncertainty, Information, and Communication.”

We would like to thank all contributors to these volumes not only for their cooperation in helping expedite on-time production but also for voluntary efforts contributed in reading and commenting on each other's essays. In addition, we acknowledge with thanks the help of the following outside referees: Chuck Blackorby, Mark Johnson, Mark Machina, John McMillan, and Joel Sobel.

Special thanks go to Deborah Bailey who coordinated our (sometimes chaotic) correspondence among authors, editors, and publisher; she cheerfully dealt with potential disasters and enabled us to deliver the completed manuscript as scheduled. Also, we would like to thank Colin Day and his staff at Cambridge University Press for a highly professional effort at their end.

Finally, and most importantly, we speak for all contributors in thanking Kenneth Arrow for being an inspirational teacher and colleague over the years. The intellectual standards he set and the enthusiasm with which he approaches our subject are surely part of all of us. We can only hope that these essays convey some sense of our appreciation and esteem.