摘要
回归模型参数的时变性会严重影响模型的拟合程度和预测效果。基于卡尔曼滤波的时变参数模型需要估计很多的参数,因而造成效率损失。基于傅里叶变换建立一个简单的变系数回归模型,给出估计方法并证明参数收敛于真实值,并给出了模型设定检验的方法。通过蒙特卡洛模拟表明:新建立的时变参数回归模型能很好地处理连续的、随机的和跳跃的时变参数模型。最后,将新建立的方法应用于研究股市联动关系,发现:不考虑系数的时变性可能给出误导性结论,考虑时变性能捕捉更为丰富的联动特征。
The time-varying characteristics of parameters in regression model can deteriorate the fitness and forecasting.The time-varying model based on Kalman?filtering has many parameters to estimate,which can lead to inefficiency.This paper introduces a time-varying model based on Fourier transformation and shows that the estimators of parameters converge to the true value.Via simulations,we show that the new time-varying model can deal with the continuous,random and abrupt time-varying parameters.Then,the new method is used to examine the co-movement relationship between stock market of China and that of US.The empirical results imply that the time-varying model can capture more abundant interaction,while the classical model can obtain misleading conclusions.
引文
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(1)误差项服从独立同分布时,传统F检验具有良好的有限样本表现。