Abstract This paper generalizes the univariate unit root test proposed by Sollis (2009) by adding correlated covariates for a power boost. The asymptotic distribution of the proposed test is derived, and the asymptotic critical values are tabulated. Simulation experiments are conducted to...

This article employs Hansen's (1995) Covariate Augmented Dickey-Fuller (CADF) test to reexamine the issue of Purchasing Power Parity (PPP) using post-Bretton Woods exchange rate data for 20 industrialized countries. Instead of just using a single covariate as in the literature, we implement the...

A set of unit root tests are applied to test the existence of long-run real interest rate parity among the G-10 countries over the period 1971M1 to 2007M2. Rather than trusting the asymptotic distributions, this article uses simulation techniques to establish the small sample distributions of...

Mixed results for unemployment dynamics are reported in many studies using linear or non-linear unit root tests. A possible explanation is that the literature focuses on the average behavior of unemployment and assumes that the speed of adjustment towards its long-run equilibrium is constant,...

This paper investigates the stationarity properties of international inflation rates by bootstrapping two stationarity tests with covariates in Jansson (2004). When the asymptotic critical values are used, the two powerful tests are found to reject the null hypothesis less in the presence of a...

In this paper, we intend to develop a new unit root testing procedure. The novelty of this methodology includes (1) accommodating possible trend breaks of unknown number, unknown dates, and unknown form by employing the Fourier form without directly estimating such breaks; (2) considering...