It is perhaps early to draw lessons from the crisis that has hit the global economy. The crisis appears severe and widespread, its effects far-reaching and long-lasting. Measures of various kinds have been taken or are in the process of being taken regarding monetary policy, the use of public resources and the revision of rules and institutions on which the proper functioning of the markets and the operation of financial intermediaries depend. The present is undoubtedly a period of maximum efforts on the part of economic policy and overall political action, efforts that are directly proportional to the seriousness of the crisis. But this is also a moment in which the interpretative models used in analyzing our economies start being reconsidered and attempts are being made at identifying the reasons underlying the failures of markets, economic policies and economists’ forecasts. Besides, this is also necessary in order to better define interventions – global, substantial, focused and lasting – aimed at overcoming the crisis and, as far as possible, preventing, with the design of new rules, new institutions and new policies, such serious instability from occurring again. If overcoming the crisis will be arduous and complex, the process of revising the theoretical and quantitative frameworks of analysis, and the domestic and supranational guidelines and instruments of economic and financial policy will be equally difficult and laborious.