In this paper we propose a test of the null hypothesis of time series linearity against a nonlinear alternative, when uncertainty exists as to whether or not the series contains a unit root. We provide a test statistic that has the same limiting null critical values regardless of whether the...

We investigate nominal exchange rates and nominal price convergence in the West African Monetary Zone. Using data for the first quarter of 1974 through the first quarter of 2007, we find that real exchange rates in The Gambia, Ghana, Nigeria, and Sierra Leone follow a random walk. Further, we...

This paper develops a procedure for testing hypotheses on the full set of cointegration parameters of the I(2) model. The proposed test is applied to the analysis of small-country import price determination extending the standard empirical framework to allow for variables integrated of order...