Semiparametric Tests for Double Unit Roots Based on Symmetric Estimators
基于对称估计量的双重单位根半参数检验
The authors develop new semiparametric tests for double unit roots under a weakly dependent error structure of Phillips for tests for a unit root. The tests are based on symmetric estimation of Sen and Dickey. Through Monte Carlo simulations, the new tests are compared with the tests of Haldrup and of Dickey and Pantula. Their tests have empirical sizes close to the nominal size even when the innovations follow a negatively autocorrelated moving average, for which the…