Orthogonality tests with de-trended data: Interpreting Monte-Carlo results using Nagar expansions

We extend previous results concerning the behaviour of a finite-sample approximation to the distribution of the t-statistic used in testing orthogonality of a variable to a given information set. In particular, we look at the case in which the data are de-trended, innovations in the explanatory variable are correlated with the regressand, and the explanatory variable is substantially autocorrelated.Publicad