TY - CHAP AB - Abstract An extensive literature in econometrics focuses on finding the exact and approximate first and second moments of the least-squares estimator in the stable first-order linear autoregressive model with normally distributed errors. Recently, Kiviet and Phillips (2005) developed approximate moments for the linear autoregressive model with a unit root and normally distributed errors. An objective of this paper is to analyze moments of the estimator in the first-order autoregressive model with a unit root and nonnormal errors. In particular, we develop new analytical approximations for the first two moments in terms of model parameters and the distribution parameters. Through Monte Carlo simulations, we find that our approximate formula perform quite well across different distribution specifications in small samples. However, when the noise to signal ratio is huge, bias distortion can be quite substantial, and our approximations do not fare well. VL - 33 SN - 978-1-78441-183-1/0731-9053 DO - 10.1108/S0731-905320140000033003 UR - https://doi.org/10.1108/S0731-905320140000033003 AU - Bao Yong AU - Ullah Aman AU - Zhang Ru PY - 2014 Y1 - 2014/01/01 TI - Moment Approximation for Least-Squares Estimator in First-Order Regression Models with Unit Root and Nonnormal Errors T2 - Essays in Honor of Peter C. B. Phillips T3 - Advances in Econometrics PB - Emerald Group Publishing Limited SP - 65 EP - 92 Y2 - 2024/04/23 ER -