Why are banking systems unstable in so many countries--but not in others? The United States has had twelve systemic banking crises since 1840, while Canada has had none. The banking systems of Mexico and Brazil have not only been crisis prone but have provided miniscule amounts of credit to business enterprises and households. Analyzing the political and banking history of the United Kingdom, the United States, Canada, Mexico, and Brazil through several centuries, Fragile by Design demonstrates that chronic banking crises and scarce credit are not accidents. Calomiris and Haber combine political history and economics to examine how coalitions of politicians, bankers, and other interest groups form, why they endure, and how they generate policies that determine who gets to be a banker, who has access to credit, and who pays for bank bailouts and rescues. Fragile by Design is a revealing exploration of the ways that politics inevitably intrudes into bank regulation.