Predicting crises, part I: Do coming crises cast their shadows before?

The enormity of the current financial collapse, widely described as a bursting bubble, raises the question whether the crisis could have been predicted, possibly permitting action to offset its effects. In the first of two Economic Letters on the subject, we look at developments in the United States and find evidence suggesting that simple indicators based on asset market developments can provide early warnings about potentially dangerous financial imbalances.