Nielsen (2004) provides multivariate maximum likelihood procedures to test whether several series are fractionally integrated. This note examines the finite sample size of the likelihood ratio tests applied to a bivariate system experiencing breaks in means. The results suggest that tests of a...

Lopez et al. (2005) demonstrated that single-equation unit-root tests cannot provide conclusive evidence of whether real exchange rates are stationary because inference depends critically on the lag-lengths used to construct the test statistics, a result reinforced by a recent work by Sweeney...