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协整系统中的结构变化检验AI 解读

This paper considers tests for structural change of the cointegrating vector and the adjustment vector in the error correction model with an unknown change point. This paper derives new tests for structural change, which are applicable to maximum likelihood estimation. Our tests for structural change of the cointegrating vector have the same nonstandard asymptotic distributions that have been found by Hansen (1992a, Journal of Business and Economic Statistics 10, 321–335).…

时变参数模型中系数方差的中位数无偏估计AI 解读

This article considers inference about the variance of coefficients in time-varying parameter models with stationary regressors. The Gaussian maximum likelihood estimator (MLE) has a large point mass at 0. We thus develop asymptotically median unbiased estimators and asymptotically valid confidence intervals by inverting quantile functions of regression-based parameter stability test statistics, computed under the constant-parameter null. These estimators have good…

带生存结局的面板数据：HIV 阳性患者住院分析AI 解读

This article provides an analysis of the hospitalization experience of a panel of HIV-positive patients. It is part of a program of work designed to study the medical expenditures of such patients and their variation both between people and over time. We model the joint distribution of the inpatient episodes and the survival times of a panel of patients over 15 months. The model induces correlation between hospitalization and death via an unmeasured, person-specific, frailty…

时间序列分析在天文学和气象学中的应用AI 解读

Part 1 Time series - theory and methodology: A short history of time series, M.B. Priestley Frequency estimation, E.J. Hannan et al Asymptotic expansion of estimators for diffusions with small noises, N. Yoshida Spatial-temporal spectral analysis with random sampling, I-Shang Chow, Ken-Shin Lii Detection of periodicities, M.B. Priestley Spectral and multivariate probability density estimation of continuous time stationary processes from randomly sampled data, Elias Masry…

周期性状态转换模型的贝叶斯推断AI 解读

We present a general class of nonlinear time-series Markov regime-switching models for seasonal data which may exhibit periodic features in the hidden Markov process as well as in the laws of motion in each of the regimes. This class of models allows for non-trivial dependencies between seasonal, cyclical and long-term patterns in the data. To overcome the computational burden we adopt a Bayesian approach to estimation and inference. This paper contains two empirical…

局部平稳过程的自适应协方差估计AI 解读

It is shown that the covariance operator of a locally stationary process has approximate eigenvectors that are local cosine functions. We model locally stationary processes with pseudo-differential operators that are time-varying convolutions. An adaptive covariance estimation is calculated by searching first for a "best" local cosine basis which approximates the covariance by a band or a diagonal matrix. The estimation is obtained from regularized versions of the diagonal…

摘要暂缺

存在序列相关时的趋势函数假设检验AI 解读

Test statistics are proposed for testing hypotheses about the parameters of the deterministic trend function of a univariate time series. The tests are valid for general forms of serial correlation in the errors and do not require estimates (parametric or nonparametric) of serial correlation parameters. The tests are valid for stationary and unit root errors. Allowable trend functions include linear polynomials of time that may have structural change. Asymptotic results are…

含多重结构变化的线性模型：估计与检验AI 解读

This paper develops the statistical theory for testing and estimating multiple change points in regression models. The rate of convergence and limiting distribution for the estimated parameters are obtained. Several test statistics are proposed to determine the existence as well as the number of change points. A partial structural change model is considered. The authors study both fixed and shrinking magnitudes of shifts. In addition, the models allow for serially correlated…

无需估计序列相关参数的均值突变检验AI 解读

Tests for detecting a shift in the mean of univariate time series that do not require estimation of serial-correlation parameters are proposed. The statistics are valid whether the errors are stationary or have a unit root. The date of the shift may be known or unknown. The statics are based on a simple transformation of the data and are functions of partial sums of the data. These so-called partial sum statistics are shown to be asymptotically invariant to…

具有时变系数的 Cox 回归模型拟合检验AI 解读

This paper examines goodness-of-fit testing in the Cox regression model with time-varying regression coefficients. Arjas' (1988) approach is used to define test statistics of the Kolmogorov-Smirnov and Cramér-von Mises types. Their asymptotic limits are shown to be well-known functionals of standard Brownian motion, leading to the construction of formal goodness-of-fit tests. Some numerical studies are also included to illustrate the performance of the tests for moderate…

分段凸函数估计：初步估计量AI 解读

Given noisy data, function estimation is considered when the unknown function is known a priori to be either convex or concave on each of a small number of regions where the function. When the number of regions is unknown, the model selection problem is to determine the number of convexity change points. For kernel estimates in Gaussian noise, the number of false change points is evaluated as a function of the smoothing parameter. To insure that the number of false convexity…

确定身体质量指数与死亡率关系的最低点：案例研究AI 解读

Many studies have demonstrated a nonmonotonic relationship between mortality and body mass index (BMI), with excess mortality occurring at both low and high levels. Although much discussion and many different analyses have appeared, to our knowledge no attempt has been made to quantitatively establish the BMI at which minimum mortality (BMImin) occurs or to establish confidence intervals for this BMI, accounting for the asymmetry of the relationship. We model the…

检测动态时间序列趋势函数断点的 Wald 型检验AI 解读

In this paper, test statistics for detecting a break at an unknown date in the trend function of a dynamic univariate time series are proposed. The tests are based on the mean and exponential statistics of Andrews and Ploberger (1994, Econometrica 62, 1383–1414) and the supremum statistic of Andrews (1993, Econometrica 61, 821–856). Their results are extended to allow trending and unit root regressors. Asymptotic results are derived for both I (0) and I (1) errors. When the…

非对称损失下的最优预测AI 解读

Prediction problems involving asymmetric loss functions arise routinely in many fields, yet the theory of optimal prediction under asymmetric loss is not well developed. We study the optimal prediction problem under general loss structures and characterize the optimal predictor. We compute the optimal predictor analytically in two leading tractable cases and show how to compute it numerically in less tractable cases. A key theme is that the conditionally optimal forecast is…

分布变化最优检测札记AI 解读

Suppose $X_1, X_2, \dots, X_{\nu - 1}$ are iid random variables with distribution $F_0$, and $X_{\nu}, X_{\nu + 1}, \dots$ are are iid with distributed $F_1$. The change point $\nu$ is unknown. The problem is to raise an alarm as soon as possible after the distribution changes from $F_0$ to $F_1$ (detect the change), but to avoid false alarms. Pollak found a version of the Shiryayev-Roberts procedure to be asymptotically optimal for the problem of minimizing the average run…

生存数据中变点的似然比检验AI 解读

We consider the likelihood ratio test for a changepoint or lag of the effect of some covariates, e.g. treatment, in regression modelling of survival data subject to right censoring. Asymptotic distributions under null hypotheses are derived. Numerical examples are used to illustrate the implementation of the procedure. Finally we apply the theory to data from a large randomised cancer prevention trial.

变点问题的鞅方法AI 解读

The changepoint problem for a binary sequence is considered. A test statistic based on recursive residuals is compared to the test statistic suggested by Pettitt. The new test statistic has more interesting properties for use in sequential testing. However, neither of the two test statistics dominates the other. Sequential versions of the martingale-based test, forward and reverse, are given and compared to other tests by means of a simulation study. The reverse martingale…

美国与荷兰的食品统计需求函数AI 解读

This paper reports results of an extensive analysis of statistical demand functions for food using household survey data and aggregate time-series data on food consumption in the USA and The Netherlands. Using the model put forward by Tobin (1950) for survey data, we find that socio-economic information on the composition, education, and status of households adds little to the explanation of food consumption. The income elasticity of food consumption decreases over time in…

美国与荷兰食品需求建模的比较研究AI 解读

This paper provides time-series and cross-sectional budget survey analyses of the demand for food in the United States and the Netherlands according to the tasks set by Jan Magnus and Mary Morgan (MM). Various econometric methods, including weighted least squares (WLS), cointegration, error correction, the almost ideal demand system (AIDS), and time-varying parameter (TVP) techniques, are used and the estimated demand elasticities compared across country and over time.

重复测量剂量—反应关系的随机效应阈值模型AI 解读

Summary A random threshold model for dose--response designs with repeated measurements is introduced. Inference procedures for this model are discussed. The framework of generalized linear models is used to propose a quasi-likelihood inference procedure. The feasibility of this approach is illustrated with the analysis of food science data concerning a forced choice sensory experiment.

摘要暂缺

通胀率存在单位根吗？序贯突变与面板模型的证据AI 解读

Using sequential trend break and panel data models, we investigate the unit root hypothesis for the inflation rates of thirteen OECD countries. With individual country tests, we find evidence of stationarity in only four of the thirteen countries. The results are more striking with the panel data model. We can strongly reject the unit root hypothesis both for a panel of all thirteen countries and for a number of smaller panels consisting of as few as three countries. The…

方差变点的检验与定位及其股票价格应用AI 解读

This article explores testing and locating multiple variance changepoints in a sequence of independent Gaussian random variables (assuming known and common mean). This type of problem is very common in applied economics and finance. A binary procedure combined with the Schwarz information criterion (SIC) is used to search all of the possible variance changepoints existing in the sequence. The simulated power of the proposed procedure is compared to that of the CUSUM…