非参数计量经济联立模型的局部线性两阶段最小二乘变窗宽估计

联立方程模型在经济政策制定、经济结构分析和经济预测方面起重要作用 .本文在随机设计 (模型中所有变量为随机变量 )下 ,提出了非参数计量经济联立模型的局部线性两阶段最小二乘变窗宽估计并利用概率论中大数定理和中心极限定理在内点处研究了它的大样本性质 ,证明了它的一致性和渐近正态性 .它在内点处的收敛速度达到了非参数函数估计的最优收敛速度 .     

非参数计量经济联立模型的局部线性两阶段最小二乘估计

联立方程模型在经济政策制定，经济结构分析和经济预测方面起重要作用，本在随机设计（模型中所有变量为随机变量）下，提出了非参数计量经济联立模型的局部线性两阶段最小二乘估计并利用概率论中大数定理和中心极限定理在内点处研究了它的大样本性质，证明了它的一致性和渐近正态性，它在内点处的收敛速度达到了非参数函数估计的最优收敛速度。     

半参数面板空间滞后模型的两阶段最小二乘估计及应用

发展了一种半参数面板空间滞后模型的两阶段最小二乘估计方法.证明了参数分量估计具有渐近正态性且收敛速度为n~(-1/2),非参数分量估计在内点处具有渐近正态性,其收敛速度达到了非参数函数估计的最优收敛速度.并将方法应用于外商直接投资对劳动收入份额的影响分析.     

单边截断型分布族位置参数的经验Bayes估计的收敛速度

本文对一般的单边截断型分布族,构造了位置参数θ的经验Beyes估计,并建立了它的收敛速度,在一定条件下这个收敛速度可任意接近1/2。最后也给出了满足定理1和定理 2条件的一些例子。     

NA样本及Linex损失下截断族参数的经验EB估计

在Linex损失及NA样本下 ,对一类双边截断型分布族 ,构造了参数的经验Bayes(EB)估计 ,建立了它的收敛速度 .在一定的条件下证明了该收敛速度可以任意接近于 1 ,并给出满足定理条件的例子 .     

小波级数的部分和的逐点收敛性

对小波级数的部分和的逐点收敛性进行了讨论,通过引入函数空间L2r(R),研究了函数f∈L2r(R)的小波级数的部分和fn的r阶导数对f(r)的逐点逼近问题.当函数f(r)在点x处连续时,建立了逼近速度的一个精确估计,进而得到了相关的逐点收敛定理.其次,当点x为函数f(r)的第一类间断点时,建立了f(r)n对f(r)在点x处的左右极限的算术平均值的收敛速度的一个估计.     

NA样本下截断型分布族参数的经验Bayes估计

运用NA样本密度函数核估计构造了一类截断型分布族参数的经验Bayes估计，建立了它的收敛速度，证明了在适当条件下该收敛速度可以任意接近于1，文中还给出了适合定理条件的例子。     

具有连续参数的宽平稳随机场的采样定理及应用

研究具有连续参数的宽平稳随机场的采样定理,并求出它的相关函数;谱密度函数和谱函数的估计式以及它们的一致收敛的速度.     

对称的稳定分布参数变点估计的相合性

假设稳定分布的特征指数α满足1<α<2,关于均值μ对称. 本文讨论了稳定分布中α或刻度参数β的变化导致的变点问题,即是否发生变化及变化时刻.若均值已知,当α或β改变时,密度函数f(x)在μ处的值f(μ)发生变化,我们利用密度函数的核估计来估计该点的值. 若均值未知,利用经验特征函数估计该点的值,并进一步讨论了估计的相合性与收敛速度. 其次讨论了均值变化导致的变点问题,若均值发生变化,相应变点前后特征函数的参数将变化,利用经验特征函数给出了变点的估计, 获得了类似的收敛速度. 最后给出了检测金融市场突变性的应用.     

双指数分布位置参数的经验Bayes估计问题

本文在平方损失下导出了双指数分布位置参数的Bayes估计，利用非参数方法构造了位置参数的经验Bayes(EB)估计．在适当的条件下，获得了EB估计的收敛速度．最后，给出了一个例子说明适合定理条件的先验分布是存在的．     

Semiparametric mixtures of regressions with single-index for model based clustering

In this article, we propose two classes of semiparametric mixture regression models with single-index for model based clustering. Unlike many semiparametric/nonparametric mixture regression models that can only be applied to low dimensional predictors, the new semiparametric models can easily incorporate high dimensional predictors into the nonparametric components. The proposed models are very general, and many of the recently proposed semiparametric/nonparametric mixture regression models are indeed special cases of the new models. Backfitting estimates and the corresponding modified EM algorithms are proposed to achieve optimal convergence rates for both parametric and nonparametric parts. We establish the identifiability results of the proposed two models and investigate the asymptotic properties of the proposed estimation procedures. Simulation studies are conducted to demonstrate the finite sample performance of the proposed models. Two real data applications using the new models reveal some interesting findings.

     

缺失数据下非线性半参数EV模型的估计

考虑解释变量带有测量误差且响应变量随机缺失情形下的非线性半参数EV模型. 利用核实数据,构造了未知参数和非参数函数的两种估计.证明了未知参数估计的渐近正态性,给出了非参数函数估计的最优收敛速度.     

漂移向量与扩散矩阵的非参数估计模型

考虑多维扩散过程的非参数估计问题.利用It扩散的性质,将漂移向量和扩散矩阵的样本表示成带有测量误差的回归模型,并讨论了系统误差的L~r上界以及随机误差项的收敛速度,建立了漂移向量与扩散矩阵非参数估计的通用模型.     

Some uniform convergence results for kernel estimators

This paper derives some uniform convergence rates for kernel regression of some index functions that may depend on infinite dimensional parameter. The rates of convergence are computed for independent, strongly mixing and weakly dependent data respectively. These results extend the existing literature and are useful for the derivation of large sample properties of the estimators in some semiparametric and nonparametric models.     

因变量缺失下部分线性变系数变量含误差模型的估计

该文主要考虑部分线性变系数模型在自变量含有测量误差以及因变量存在缺失情形下的估计问题.基于Profile最小二乘技术,针对参数分量和非参数分量提出了多种估计方法.第一种估计方法只利用了完整观测数据,而第二种和第三种估计方法分别利用了插补技术和替代技术.参数分量的所有估计被证明是渐近正态的,非参数分量的所有估计被证明和一般非参数回归函数的估计具有相同的收敛速度.对于因变量的均值,构造了两类估计并证明了它们的渐近正态性.最后,通过数值模拟验证了所提方法.     

Complete f-moment Convergence for Widely Orthant Dependent Random Variables and Its Application in Nonparametric Models

In this paper, we study the complete f-moment convergence for widely orthant dependent (WOD, for short) random variables. A general result on complete f-moment convergence for arrays of rowwise WOD random variables is obtained. As applications, we present some new results on complete f-moment convergence for WOD random variables. We also give an application to nonparametric regression models based on WOD errors by using the complete convergence that we established. Finally, the choice of the fixed design points and the weight functions for the nearest neighbor estimator are proposed, and a numerical simulation is provided to verify the validity of the theoretical result.     

Asymptotic theory of nonparametric regression estimates with censored data

For regression analysis, some useful information may have been lost when the responses are right censored. To estimate nonparametric functions, several estimates based on censored data have been proposed and their consistency and convergence rates have been studied in literature, but the optimal rates of global convergence have not been obtained yet. Because of the possible information loss, one may think that it is impossible for an estimate based on censored data to achieve the optimal rates of global convergence for nonparametric regression, which were established by Stone based on complete data. This paper constructs a regression spline estimate of a general nonparametric regression function based on right_censored response data, and proves, under some regularity conditions, that this estimate achieves the optimal rates of global convergence for nonparametric regression. Since the parameters for the nonparametric regression estimate have to be chosen based on a data driven criterion, we also obtain the asymptotic optimality of AIC, AICC, GCV, Cp and FPE criteria in the process of selecting the parameters.     

Stahel-Donoho kernel estimation for fixed design nonparametric regression models

This paper reports a robust kernel estimation for fixed design nonparametric regression models. A Stahel-Donoho kernel estimation is introduced, in which the weight functions depend on both the depths of data and the distances between the design points and the estimation points. Based on a local approximation, a computational technique is given to approximate to the incomputable depths of the errors. As a result the new estimator is computationally efficient. The proposed estimator attains a high breakdown point and has perfect asymptotic behaviors such as the asymptotic normality and convergence in the mean squared error. Unlike the depth-weighted estimator for parametric regression models, this depth-weighted nonparametric estimator has a simple variance structure and then we can compare its efficiency with the original one. Some simulations show that the new method can smooth the regression estimation and achieve some desirable balances between robustness and efficiency.