The aim of this study is to search for a better optimization algorithm in applying unit root tests that inherit nonlinear models in the testing process. The algorithms analyzed include Broyden, Fletcher, Goldfarb and Shanno (BFGS), Gauss-Jordan, Simplex, Genetic, and Extensive Grid-Search. The...

In this paper we introduce an autoregressive model with a deterministically shifting intercept. This implies that the model has a shifting mean and is thus nonstationary but stationary around a nonlinear deterministic component. The shifting intercept is defined as a linear combination of...

In this paper we introduce an autoregressive model with a deterministically shifting intercept. This implies that the model has a shifting mean and is thus nonstationary but stationary around a nonlinear deterministic component. The shifting intercept is defined as a linear combination of...

This paper replicates Leybourne et al. (1998), who propose a Dickey-Fuller type test for unit root that is most appropriate when there is reason to suspect the possibility of deterministic structural change in the series. We find that our replicated results are quite similar to the authors'...

For both deterministic or stochastic regressors, as well as parametric nonlinear or linear regression functions, we prove the weak consistency of the coefficient estimators for the Type I censored quantile regression model under different censoring mechanisms with censoring points depending on...

We extend the class of M-tests for a unit root analyzed by Perron and Ng (1996) and Ng and Perron (1997) to the case where a change in the trend function is allowed to occur at an unknown time. These tests M(GLS) adopt the GLS detrending approach of Dufour and King (1991) and Elliott, Rothenberg...

When using quasi-differenced data in a model where a break in the intercept is allowed, asymptotic distributions of the M, ADF, and PT statistics are the same as those in the model where only an intercept and a time trend are included. However, the finite sample behaviour for common sample sizes...

This paper provides evidence of long run purchasing power parity by performing a recently developed method to test for unit roots in the presence of structural breaks. Data consist of real exchange rate series for 20 countries including developed and developing economies. Structural breaks are...

This paper provides evidence of long run purchasing power parity by performing a recently developed method to test for unit roots in the presence of structural breaks. Data consist of real exchange rate series for 20 countries including developed and developing economies. Structural breaks are...