We provide a new definition of breakdown in finite samples with an extension to asymptotic breakdown. Previous definitions center around defining a critical region for either the parameter or the objective function. If for a particular outlier constellation the critical region is entered,...

We consider fixed-smoothing asymptotics for the Diebold and Mariano (1995) test of predictive accuracy. We show that this approach delivers predictive accuracy tests that are correctly sized even when only a small number of out of sample observations are available. We apply the fixed-smoothing...