The observed persistence common in economic time series may arise from a variety of models that are not always distinguished with confidence in practice, yet play an important role in model specification and second stage inference procedures. Previous literature has introduced causality tests...

We propose a modified version of the nonparametric level crossing random walk test, in which the crossing level is determined locally. This modification results in a test that is robust to unknown multiple structural breaks in the level and slope of the trend function under both the null and...