In several recent articles, authors have regressed actual values of macroeconomic aggregates on predicted values and claimed that they were testing the rationality of expectations. This paper interprets those regressions as testing a joint hypothesis of imperfect information and rational...

Thirty years ago it appeared that the best strategy for improving economic forecasts was to build bigger, more detailed models. As the cost of computing plummeted, considerable detail was added to models and more elaborate statistical techniques became feasible. Yet dissatisfaction with...