Although our names appear on the book cover, the contents benefited enormously from insightful conversations with many colleagues, the detailed comments of those who suffered through early versions of the manuscript, seminar and conference participants literally all over the world, and the extraordinary help of many research assistants. At various stages of putting together the database and checking the results, we received excellent assistance from Xin Chen, Dan Goldblum, Andy Kim, and Iffath Sharif; Polly Means assisted with Figure 1.1 and the cover with her usual skill. Daniele Evans kept Jerry organized while he was working on the book and defended him from some bureaucratic demands with great skill, and she and Elena Mehkova helped on parts of the manuscript. We are especially grateful to Cindy Lee and Triphon Phumiwasana for their tireless efforts in assisting us with the database during the past few years. We also benefited from extensive comments from a number of scholars working in this or related areas, and we owe a debt to Thorsten Beck, John Boyd, Charles Calomiris, Maria Carkovic, Stijn Claessens, Asli Demirgüç-Kunt, Bill Easterly, Morris Goldstein, Charles Goodhart, Stephen Haber, Jim Hanson, Patrick Honohan, Ed Kane, George Kaufman, Luc Laeven, Juan Marchetti, Rick Mishkin, Dan Nolle, Larry Promisel, Raghu Rajan, Joao Santos, Augusto de la Torre, Andrei Shleifer, and Greg Udell for comments both general and specific.