This paper analyzes hypotheses and evidence for the causes of the Asian crises. It presents new evidence that, along with high rates of credit expansion and low ratios of international reserves to short-term debt, the combination of substantially appreciated currencies and large current account deficits played an important role in the crises' severity. Furthermore, the paper concludes that pre-crisis over-optimism rather than panic caused financial markets to behave imperfectly and that perverse financial liberalization and limited flexibility of exchange rates generated moral hazard problems of more importance than those generated by prospects of international bailouts.