H-likelihood: problems and solutions

In recent issues of this journal it has been asserted in two papers that the use of h-likelihood is wrong, in the sense of giving unsatisfactory estimates of some parameters for binary data (Kuk and Cheng, 1999; Waddington and Thompson, 2004) or theoretically unsound (Kuk and Cheng, 1999). We wish to refute both these assertions.     

环境保护综合措施的探讨

简述了我国市场经济条件下环境保护的特点,对限制措施和利益机制的效果及相互作用进行了图示分析,指出我国的环境治理必须运用法律措施和经济措施进行综合整治。并提出了运用法律措施和经济措施调控环境的一些基本思路和方法。     

Semiparametric log-linear regression for longitudinal measurements subject to outcome-dependent follow-up

A common problem for longitudinal data analyses is that subjects follow-up is irregular, often related to the past outcome or other factors associated with the outcome measure that are not included in the regression model. Analyses unadjusted for outcome-dependent follow-up yield biased estimates. We propose a longitudinal data analysis that can provide consistent estimates in regression models that are subject to outcome-dependent follow-up. We focus on semiparametric marginal log-link regression with arbitrary unspecified baseline function. Based on estimating equations, the proposed class of estimators are root n consistent and asymptotically normal. We present simulation studies that assess the performance of the estimators under finite samples. We illustrate our approach using data from a health services research study.     

The Relative Size of Windfall Income and the Permanent Income Hypothesis

A reconciliation is offered for the diverse test results on Friedman's permanent income hypothesis. A large data sample of those receiving windfall income in the Bureau of Labor Statistics' 1972–1973 Consumer Expenditure Survey is divided according to the size of the windfall relative to estimated permanent income. A pattern of a declining marginal propensity to consume windfall income as the relative size of the windfall increases is apparent. These results support the permanent income hypothesis for relatively large windfalls.     

Marginal Changes in Random Parameters Ordered Response Models with Interaction Terms

Marginal changes of interacted variables and interaction terms in random parameters ordered response models are calculated incorrectly in econometric softwares. We derive the correct formulas for calculating these marginal changes. In our empirical example, we observe significant changes not only in the magnitude of the marginal effects but also in their standard errors, suggesting that the incorrect estimation of the marginal effects of these variables as is commonly practiced can render biased inferences on the findings.     

Composite Marginal Likelihoods to the Normal Bradley-Terry Model

Inference in generalized linear mixed models with crossed random effects is often made cumbersome by the high-dimensional intractable integrals involved in the marginal likelihood. This article presents two inferential approaches based on the marginal composite likelihood for the normal Bradley-Terry model. The two approaches are illustrated by a simulation study to evaluate their performance. Thereafter, the asymptotic variances of the estimated variance component are compared.     

Computing Marginal Likelihoods via Posterior Sampling

This article presents a novel and simple approach to the estimation of a marginal likelihood, in a Bayesian context. The estimate is based on a Markov chain output which provides samples from the posterior distribution and an additional latent variable. It is the mean of this latent variable which provides the estimate for the value of the marginal likelihood.     

Robust Correlation Structure for Multivariate Failure Time Data

When incomplete repeated failure times are collected from a large number of independent individuals, interest is focused primarily on the consistent and efficient estimation of the effects of the associated covariates on the failure times. Since repeated failure times are likely to be correlated, it is important to exploit the correlation structure of the failure data in order to obtain such consistent and efficient estimates. However, it may be difficult to specify an appropriate correlation structure for a real life data set. We propose a robust correlation structure that can be used irrespective of the true correlation structure. This structure is used in constructing an estimating equation for the hazard ratio parameter, under the assumption that the number of repeated failure times for an individual is random. The consistency and efficiency of the estimates is examined through a simulation study, where we consider failure times that marginally follow an exponential distribution and a Poisson distribution is assumed for the random number of repeated failure times. We conclude by using the proposed method to analyze a bladder cancer dataset.     

我国工业污染物的影子价格估计

 污染物的影子价格体现了污染物的边际减排成本。本文采用二次型方向性距离函数和 2003-2008年我国284个地级及以上城市工业部门数据,对废水、SO2和烟尘等三种污染物的影子价格进行了估计。结果发现,2003-2008年期间,废水、SO2、烟尘的影子价格或边际减排成本分别为0.0178万元/吨、5.158万元/吨和4.597万元/吨。SO2排污权交易价格相比污染减排成本偏低,影响了排污权交易市场的有效运作。污染物的影子价格在不同城市具有较大差异,这种差异性能够在一定程度上被污染排放规模、监管强度和污染治理的规模经济性等因素所解释。