In her useful new book, Gillian Tett of The Financial Times writes that the global financial meltdown, which economists estimate could result in total losses from $2 trillion to $4 trillion, was “self-inflicted.” Unlike many banking crises, she adds, “this one was not triggered by a war, a widespread recession, or any external economic shock.” Rather, the “entire financial system went wrong as a result of flawed incentives within banks and investment funds, as well as the rating agencies; warped regulatory structures; and a lack of oversight.”