Abstract
Prediction interval tests are applied to the reduced forms of two quarterly models of the U.S. (the "old" FRB-MIT model and the Michigan model). The results illustrate the range of tests one can perform on an estimated simultaneous equation model. In particular, the tests determine whether ex post forecast errors can be attributed to structural deficiencies of the models. The paper examines confidence regions and other aspects of forecast distributions-comparisons between mean forecasts and nonstochastic forecasts, comparisons between, forecast variances from multiperiod endogenous simulations and those from one period simulations, and comparisons between forecast variances and residual variances.