Credit booms buttress investment and consumption and can contribute to long-term financial deepening. But they often end up in costly balance sheet dislocations, and, more often than acceptable, in devastating financial crises whose cost can exceed the benefits associated with the boom. These risks have long been recognized. But, until the global financial crisis in 2008, policy paid limited attention to the problem. The crisis - preceded by booms in many of the hardest-hit countries - has led to a more activist stance.