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1.
AbstractThe economic mobility of individuals and households is of fundamental interest. While many measures of economic mobility exist, reliance on transition matrices remains pervasive due to simplicity and ease of interpretation. However, estimation of transition matrices is complicated by the well-acknowledged problem of measurement error in self-reported and even administrative data. Existing methods of addressing measurement error are complex, rely on numerous strong assumptions, and often require data from more than two periods. In this article, we investigate what can be learned about economic mobility as measured via transition matrices while formally accounting for measurement error in a reasonably transparent manner. To do so, we develop a nonparametric partial identification approach to bound transition probabilities under various assumptions on the measurement error and mobility processes. This approach is applied to panel data from the United States to explore short-run mobility before and after the Great Recession. 相似文献
2.
AbstractThis paper focuses on the inference of suitable generally non linear functions in stochastic volatility models. In this context, in order to estimate the variance of the proposed estimators, a moving block bootstrap (MBB) approach is suggested and discussed. Under mild assumptions, we show that the MBB procedure is weakly consistent. Moreover, a methodology to choose the optimal length block in the MBB is proposed. Some examples and simulations on the model are also made to show the performance of the proposed procedure. 相似文献
3.
Rodolphe Priam 《统计学通讯:理论与方法》2020,49(18):4468-4489
AbstractThe mean estimators with ratio depend on multiple auxiliary variables and unknown parameters in a finite population setting. We propose a new generalized approach with matrices for modeling the mutivariate mean estimators with two auxiliary variables. Our approach brings naturally a graphical analysis for comparing mean estimators. 相似文献
4.
龙江华 《湖北民族学院学报(哲学社会科学版)》2002,20(2):108-112
通过深入分析非英语专业大学生英语作文中出现的内容、篇章结构、语言表达等方面的非语法错误,提出了写前阶段构思、审题技巧训练及寓写作于精读课教学等相应的纠错策略。 相似文献
5.
On Optimality of Bayesian Wavelet Estimators 总被引:2,自引:0,他引:2
Felix Abramovich Umberto Amato Claudia Angelini 《Scandinavian Journal of Statistics》2004,31(2):217-234
Abstract. We investigate the asymptotic optimality of several Bayesian wavelet estimators, namely, posterior mean, posterior median and Bayes Factor, where the prior imposed on wavelet coefficients is a mixture of a mass function at zero and a Gaussian density. We show that in terms of the mean squared error, for the properly chosen hyperparameters of the prior, all the three resulting Bayesian wavelet estimators achieve optimal minimax rates within any prescribed Besov space for p ≥ 2. For 1 ≤ p < 2, the Bayes Factor is still optimal for (2 s +2)/(2 s +1) ≤ p < 2 and always outperforms the posterior mean and the posterior median that can achieve only the best possible rates for linear estimators in this case. 相似文献
6.
分析了影响数控火焰切割机加工精度的主要因素,利用开放式数控系统的软件开放性,提出了采用IGCAQBP学习算法的神经网络方法来对包括金属热变形、机械传动误差等非线性因素在内的多种因素造成的加工误差进行误差补偿,设计了嵌入开放式数控系统中的神经网络误差补偿器,给出了实用的补偿器使用方法,并对误差补偿功能进行了扩展,仿真结果和实际应用表明该方法稳定有效。 相似文献
7.
针对串联型稳压器,设计了一种应用于串联型稳压器具有自建基准的新型误差放大电路。该电路具有构思巧妙,结构优化,易于集成及较高的开环增益,共模抑制比及交流特性的优点。通过验证,实测数据与仿真结果基本一致。 相似文献
8.
John D. Emerson David C. Hoaglin Frederick Mosteller 《Statistical Methods and Applications》1993,2(3):269-290
Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects
model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights
the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study
variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however,
the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that
uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that
available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation
experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also
included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends
on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual
data and the differences among the results.
This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University. 相似文献
9.
Angelo Zanella 《Statistical Methods and Applications》1992,1(1):143-160
Summary For technological applications it can be useful to identify some simple physical mechanisms, which, on the basis of the available
knowledge of the production process, may suggest the most appropriate approach to statistical control of the random quantities
of interest. For this purpose the notion of rupture point is introduced firstly. A rupture point is characterized bym randomly arising out of control states, assumed to be mutually exclusive and stochastically independent. Shewhart's control
charts seem to represent the natural statistical tool for controlling a rupture point; however it is shown that they are fully
justified only when the hazard rates attached to the causes of failure are constant. Otherwise, typically in the presence
of time increasing hazard rates, Shewhart's control charts should be completed by a preventive intervention rule (preventive
maintenance). In the second place, the notion of dynamic instability point is introduced, which is specifically characterized
by assuming that the random quantity of interest is ruled by a stochastic differential equation with constant coefficients.
By discretization, developed according to a possibly new approach, it is shown that the former model reduces to an equation
error model, which is among the simplest used in adaptive control, and thus particularly easy to deal with in regard to parameter
estimation and the definition of the optimum control rule. 相似文献
10.
Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances. 相似文献