Government guarantees can help persuade private investors to finance valuable new infrastructure. But because their costs are hard to estimate and usually do not show up in the government's accounts, governments can be tempted to grant too many guarantees. Drawing on a diverse range of disciplines, including finance, history, economics, and psychology, 'Government Guarantees' aims to help governments give guarantees only when they are justified. It reviews the history of government guarantees and identifies the cognitive and political obstacles to good decisions about guarantees. It then...