摘要:Suppose that we observe(xt, yt)from the errors-in-variables model : xt=ξt+δt, yt=βξt+εt, where{δt}and{εt}are i.i.d.measurement errors. Here we assume that{ξt}is a non-Gaussian stationary process with zero mean and spectral density fξ(λ). For this model, some estimators for β have been proposed in the literature. However, they are constructed under the assumption that the data are independent normal variates. Thus they do not contain the dependent structure of the data(e.g., time-lagged sample covariances, etc.). In this paper we propose a new class Λ of estimators of β, which is defined under consideration for dependent structures of (xt, yt, ξt). Then the asymptotic distribution of β^^^∈Λ is derived. We give an asymptotically optimal estimator in this class. Comparison with the existing estimators is also discussed. Since the asymptotic variance of β^^^ is complicated we have illuminated some aspect of the asymptotics numerically using Mathematica.
关键词:errors-in-variables model;stationary process;spectral density;nonparametric spectral estimator;asymptotic distribution