A New Unit Root Test against Asymmetric ESTAR Nonlinearity with Smooth Breaks

Authors

1 Iran and Trade Promotion Organization, Allameh Tabataba'i University, Tehran, Iran

2 Department of Finance, Feng Chia University, Taichung, Taiwan

3 Faculty of Economics, University of Mazandaran, Babolsar, Iran

4 Department of Finance, National Sun Yat-sen University, Kaohsiung, Taiwan

Abstract

T





his paper proposes a new unit root test against the alternative of symmetric or asymmetric exponential smooth transition autoregressive (AESTAR) nonlinearity that accounts for multiple smooth breaks. We provide small sample properties which indicate the test statistics have good empirical size and power. Also, we compared small sample properties of the test statistics with Christopoulos and Leon-Ledesma (2010) test. The results indicate that our unit root test approach is superior to the test method of Christopoulos and Leon-Ledesma (2010) for both transition parameters (i.e. slow and fast speed), and the test power increases along with the frequency. We apply our test statistics for examining the real interest rate parity hypothesis among OECD countries.
 

Keywords


Bai, J., & Perron, P. (2003). Computation and Analysis of Multiple Structural Change Models. Journal of Applied Econometrics, 18, 1–22.
Becker, R., Enders, W., & Lee, J. (2004). A General Test for Time Dependence in Parameters. Journal of Applied Econometrics, 19, 899–906.
Becker, R., Enders, W., & Lee, J. (2006). A Stationary Test in the Presence of an Unknown Number of Smooth Breaks. Journal of Time Series Analysis, 27, 381–409.
Christopoulos, D. K., & Leon-Ledesma, M. A. (2010). Smooth Breaks and Non-Linear Mean Reversion: Post-Bretton Woods Real Exchange Rates. Journal of International Money and Finance, 29, 1076–1093.
Enders, W., & Lee, J. (2012). A Unit Root Test Using a Fourier Series to Approximate Smooth Breaks. Oxford Bulletin of Economics and Statistics, 74(4), 574–599.
Gallant, R. (1981). On the Basis in Flexible Functional Form and an Essentially Unbiased Form: The Flexible Fourier Form. Journal of Econometrics, 15, 211–353.
Rapach, D. E., & Wohar, M. E. (2004). The Persistence in International Real Interest Rates. International Journal of Finance and Economics, 9, 339–346.
Sollis, R. (2009). A Simple Unit Root Test against Asymmetric STAR Nonlinearity with an Application to Real Exchange Rates in Nordic Countries. Economic Modelling, 26, 118–125.