Recent papers have proposed a split-sample prediction method to test for structural stability in GMM estimation when the potential break date is treated as known. In this note, the author derives the limiting distribution of the supremum of this test over all possible break dates, thus allowing...

This paper focuses on the construction of forecasts over long horizons where a typical, long-horizon forecast might span four years using twenty to forty years' data. It is argued that the presence of persistence in the form of unit or near-unit autoregressive roots poses substantial...