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基于对称估计量的双重单位根半参数检验AI 解读

The authors develop new semiparametric tests for double unit roots under a weakly dependent error structure of Phillips for tests for a unit root. The tests are based on symmetric estimation of Sen and Dickey. Through Monte Carlo simulations, the new tests are compared with the tests of Haldrup and of Dickey and Pantula. Their tests have empirical sizes close to the nominal size even when the innovations follow a negatively autocorrelated moving average, for which the…

札记：删失数据的线性变换模型AI 解读

Recently Cheng, Wei & Ying (1995, 1997) proposed a class of estimation procedures for semiparametric linear transformation models with censored observations. When the support of the censoring variable is shorter than that of the failure time, the estimators are asymptotically biased. In this paper, we present a simple modification of Cheng's estimation procedures for the regression parameters. Through extensive numerical studies with practical sample sizes, we find that the…

数据报告延迟下含协变量右删失生存分布的局部有效估计AI 解读

For many sources of survival data, there is a delay between the recording of vital status and its availability to the analyst, and the Kaplan-Meier estimator is typically inconsistent in these situations. In this paper we identify the optimal estimation problem. As a result of the curse of dimensionality, no globally efficient nonparametric estimator exists with a good practical performance at moderate sample sizes. Following the approach of Robins & Rotnitzky (1992), given…

有限半参数混合模型中广义Pólya urn方案的指数后验一致性AI 解读

Advances in Markov chain Monte Carlo MCMC methods now make it computationally feasible and relatively straightforward to apply the Dirichlet process prior in a wide range of Bayesian nonparametric problems. The feasibility of these methods rests heavily on the fact that the MCMC approach avoids direct sampling of the Dirichlet process and is instead based on sampling the finite-dimensional posterior which is obtained from marginalizing out the process. In application, it is…

广义线性模型中参数与半参数设定的检验AI 解读

We consider a generalized partially linear model E(Y|X, T) = G{X T β + m(T)}, where G is a known function, β is an unknown parameter vector, and m is an unknown function. We introduce a test statistic that allows one to decide between a parametric and a semiparametric model: (a) m is linear (i.e., m(t) = t T γ for a parameter vector γ), and (b) m is a smooth (nonlinear) function. Under linearity (a), we show that the test statistic is asymptotically normal. Moreover, we…

单元格含多个计数的双因素计数数据分析AI 解读

Multiple counts may occur in each cell of an a × b two-way layout (balanced or unbalanced) of two fixed factors A and B. Standard log-linear model analysis based on a Poisson distribution assumption of the cell counts is not applicable here, because of the unbalanced nature of the table or because the Poisson distribution assumption is not valid. We develop C(α) tests for interaction and main effects assuming data to be Poisson distributed and also assuming that data within…

连接函数与方差函数未知时的拟似然回归AI 解读

We consider the multiple regression model E(y) = μ, μ = g(x T β), var(y) — [sgrave]2(μ) with predictors x, link function g, and variance function [sgrave]2(·). The aim is to reduce the assumptions in a fully parametric generalized linear model or a quasi-likelihood model by allowing the link and the variance functions to be unknown but smooth. These functions are then estimated nonparametrically, and the estimates are substituted into the quasi-likelihood function. We…

非可忽略无应答下重复结局的半参数回归AI 解读

We consider inference about the parameter β* indexing the conditional mean of a vector of correlated outcomes given a vector of explanatory variables when some of the outcomes are missing in a subsample of the study and the probability of response depends on both observed and unobserved data values; that is, nonresponse is nonignorable. We propose a class of augmented inverse probability of response weighted estimators that are consistent and asymptotically normal (CAN) for…

摘要暂缺

每格含多个计数的双因素布局分析AI 解读

Multiple counts may occur in each cell of an a × b two-way layout (balanced or unbalanced) of two fixed factors A and B. Standard log-linear model analysis based on a Poisson distribution assumption of the cell counts is not applicable here, because of the unbalanced nature of the table or because the Poisson distribution assumption is not valid. We develop C(α) tests for interaction and main effects assuming data to be Poisson distributed and also assuming that data within…

链接函数与方差函数未知的拟似然回归AI 解读

We consider the multiple regression model E(y) = μ, μ = g(x T β), var(y) — [sgrave]2(μ) with predictors x, link function g, and variance function [sgrave]2(·). The aim is to reduce the assumptions in a fully parametric generalized linear model or a quasi-likelihood model by allowing the link and the variance functions to be unknown but smooth. These functions are then estimated nonparametrically, and the estimates are substituted into the quasi-likelihood function. We…

摘要暂缺

病例对照与半参数两样本密度比模型的推断AI 解读

We consider inference in general binary response regression models under retrospective sampling plans. Prentice & Pyke (1979) discovered that inference for the odds-ratio parameter in a logistic model can be based on a prospective likelihood even though the sampling scheme is retrospective. We show that the estimating function obtained from the prospective likelihood is optimal in a class of unbiased estimating functions. Also we link casecontrol sampling with a two-sample…

利用实验数据刻画选择偏差AI 解读

Semiparametric methods are developed to estimate the bias that arises from using nonexperimental comparison groups to evaluate social programs and to test the identifying assumptions that justify matching, selection models and the method of difference in differences. Using data from an experiment on a prototypical social program and data from nonexperimental comparison groups, the authors reject the assumptions justifying matching and their extensions of it. The evidence…

德国东西部迁移意向的半参数分析：事实与理论AI 解读

East–West migration in Germany peaked at the beginning of the 1990s although the average wage gap between Eastern and Western Germany continues to average about 25%. We analyse the propensity to migrate using microdata from the German Socioeconomic Panel. Fitting a parametric Generalized Linear Model (GLM) yields non-linear residual behavior. This finding is not compatible with classical Marshallian theory of migration and motivates the semiparametric analysis. We estimate a…

半参数估计与消费者需求AI 解读

This paper considers the implementation of semiparametric methods in the empirical analysis of consumer demand. The application is to the estimation of the Engel curve relationship and uses the British Family Expenditure Survey. Household composition is modelled using an extended partially linear framework. This is shown to provide a useful method for pooling non-parametric Engel curves across households of different demographic composition. � 1998 John Wiley & Sons, Ltd.

半参数估计与消费者需求AI 解读

This paper considers the implementation of semiparametric methods in the empirical analysis of consumer demand. The application is to the estimation of the Engel curve relationship and uses the British Family Expenditure Survey. Household composition is modelled using an extended partially linear framework. This is shown to provide a useful method for pooling non-parametric Engel curves across households of different demographic composition. � 1998 John Wiley & Sons, Ltd.

配偶医保对妻子每周工时影响的参数与半参数估计比较AI 解读

Health insurance in the USA for most of the non-aged population is provided as a fringe benefit that is received by an adult family member as part of his or her compensation package. In husband and wife households health insurance is more likely to be part of the husband's compensation package than the wife's compensation package. However, when a husband does not have employer-provided health insurance, his wife may seek health insurance through an employer. Because health…

巴基斯坦农村家庭内部资源分配的半参数分析AI 解读

We estimate semiparametric Engel curves for rural Pakistan using a large household survey. This allows us to obtain consistent estimates of the effects of household size and composition on consumption patterns even when these demographic variables are correlated with an unknown function of income. The coefficients on the household composition variables are used to infer patterns of intrahousehold allocation. While there is little evidence of gender differences among…

德国东西部迁移意向的半参数分析：事实与理论AI 解读

East–West migration in Germany peaked at the beginning of the 1990s although the average wage gap between Eastern and Western Germany continues to average about 25%. We analyse the propensity to migrate using microdata from the German Socioeconomic Panel. Fitting a parametric Generalized Linear Model (GLM) yields non-linear residual behavior. This finding is not compatible with classical Marshallian theory of migration and motivates the semiparametric analysis. We estimate a…

利用无限维指数族的贝叶斯拟合优度检验AI 解读

We develop a nonparametric Bayes factor for testing the fit of a parametric model. We begin with a nominal parametric family which we then embed into an infinite-dimensional exponential family. The new model then has a parametric and nonparametric component. We give the log density of the nonparametric component a Gaussian process prior. An asymptotic consistency requirement puts a restriction on the form of the prior, leaving us with a single hyperparameter for which we…

样本选择模型的有效半参数评分估计AI 解读

A semiparametric likelihood method is proposed for the estimation of sample selection models. The method is a two-step semiparametric scoring estimation procedure based on an index restriction and kernel estimation. Under some regularity conditions, the estimator is square-root n -consistent and asymptotically normal. The estimator is also asymptotically efficient in the sense that its asymptotic covariance matrix attains the semiparametric efficiency bound under the index…

样本选择模型截距的半参数估计AI 解读

This paper provides a consistent and asymptotically normal estimator for the intercept of a semiparametrically estimated sample selection model. The estimator uses a decreasingly small fraction of all observations as the sample size goes to infinity, as in Heckman (1990). In the semiparametrics literature, estimation of the intercept has typically been subsumed in the nonparametric sample selection bias correction term. The estimation of the intercept, however, is important…