nep-ets New Economics Papers
on Econometric Time Series
Issue of 2021‒11‒08
two papers chosen by
Jaqueson K. Galimberti
Auckland University of Technology

  1. On Time-Varying VAR models: Estimation, Testing and Impulse Response Analysis By Yayi Yan; Jiti Gao; Bin Peng
  2. Multiple-index Nonstationary Time Series Models: Robust Estimation Theory and Practice By Chaohua Dong; Jiti Gao; Bin Peng; Yundong Tu

  1. By: Yayi Yan; Jiti Gao; Bin Peng
    Abstract: Vector autoregressive (VAR) models are widely used in practical studies, e.g., forecasting, modelling policy transmission mechanism, and measuring connection of economic agents. To better capture the dynamics, this paper introduces a new class of time-varying VAR models in which the coefficients and covariance matrix of the error innovations are allowed to change smoothly over time. Accordingly, we establish a set of theories, including the impulse responses analyses subject to both of the short-run timing and the long-run restrictions, an information criterion to select the optimal lag, and a Wald-type test to determine the constant coefficients. Simulation studies are conducted to evaluate the theoretical findings. Finally, we demonstrate the empirical relevance and usefulness of the proposed methods through an application to the transmission mechanism of U.S. monetary policy.
    Keywords: multivariate dynamic time series, time-varying impulse response, testing for parameter stability
    JEL: C14 C32 E52
    Date: 2021
  2. By: Chaohua Dong; Jiti Gao; Bin Peng; Yundong Tu
    Abstract: This paper proposes a class of parametric multiple-index time series models that involve linear combinations of time trends, stationary variables and unit root processes as regressors. The inclusion of the three different types of time series, along with the use of a multiple-index structure for these variables to circumvent the curse of dimensionality, is due to both theoretical and practical considerations. The M-type estimators (including OLS, LAD, Huber’s estimator, quantile and expectile estimators, etc.) for the index vectors are proposed, and their asymptotic properties are established, with the aid of the generalized function approach to accommodate a wide class of loss functions that may not be necessarily differentiable at every point. The proposed multiple-index model is then applied to study the stock return predictability, which reveals strong nonlinear predictability under various loss measures. Monte Carlo simulations are also included to evaluate the finite-sample performance of the proposed estimators.
    Keywords: multivariate dynamic time series, time-varying impulse response, testing for parameter stability
    JEL: C13 C22
    Date: 2021

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