The volatility that has hit many middle-income countries (MICs) after liberalizimg their financial markets has prompted critics to call for new policies to stabilize these boom-bust cycles. But, as Aaron Tornell and Frank Westermann point out in this book, over the last two decades most of the developing countries that have experienced lending booms and busts have also exhibited the fastest growth among MICs. Countries with more stable credit growth, by contrast, have exhibited, on average, lower growth rates. Factors that contribute to financial fragility thus appear, paradoxically, to be...