Nonparametric regression with cross‐classified responses

In this article, we develop regression models with cross‐classified responses. Conditional independence structures can be explored/exploited through the selective inclusion/exclusion of terms in a certain functional ANOVA decomposition, and the estimation is done nonparametrically via the penalized likelihood method. A cohort of computational and data analytical tools are presented, which include cross‐validation for smoothing parameter selection, Kullback–Leibler projection for model selection, and Bayesian confidence intervals for odds ratios. Random effects are introduced to model possible correlations such as those found in longitudinal and clustered data. Empirical performances of the methods are explored in simulation studies of limited scales, and a real data example is presented using some eyetracking data from linguistic studies. The techniques are implemented in a suite of R functions, whose usage is briefly described in the appendix. The Canadian Journal of Statistics 39: 591–609; 2011. © 2011 Statistical Society of Canada     

我国内地公司ADR与原股的外溢效应研究

本文以14家同时发行H股与ADR,6家同时发行B股与ADR的上市公司为样本,利用GARCH(1,1)-MA(1)模型,探讨ADR与原股报酬波动的外溢效应,以了解我国证券市场与美国证券市场的整合程度。结果发现,我国H股与ADR之间存在报酬波动性的双向相关性,B股与ADR之间存在报酬波动性的单向相关性。本文认为,投资主体差异、市场发展程度不同以及汇率制度是三个影响我国市场和美国市场整合程度的主要因素。     

Banking on fewer children: financial intermediation,fertility and economic development

This paper shows that financial intermediation can influence fertility and labor allocation decisions by raising market wages. The increase in wages induces some households to abandon “traditional” labor intensive methods of production managed at the household level and supply labor to “modern” sector firms. Since it is optimal for households in the modern sector to have fewer children, the labor allocation decision leads to lower national fertility. A panel VAR using financial intermediation, fertility and industrial employment share data in 87 countries is estimated. The empirical results show that the data are consistent with the theoretical predictions. Received: 20 October 1997/Accepted: 31 August 1998     

The Economic Efficiency of Sampling Size: The Case of Beef Trim

The economically optimal sample size in a food safety test balances the marginal costs and marginal benefits of increasing the sample size. We provide a method for selecting the sample size when testing beef trim for Escherichia coli O157:H7 that equates the averted costs of recalls and health damages from contaminated meats sold to consumers with the increased costs of testing while allowing for uncertainty about the underlying prevalence rates of contamination. Using simulations, we show that, in most cases, the optimal sample size is larger than the current sample size of 60 and, in some cases, it exceeds 120. Moreover, lots with a lower prevalence rate have a higher expected damage because contamination is more difficult to detect. Our simulations indicate that these lots have a higher optimal sampling rate.     

Welfare generosity, pregnancies and abortions among unmarried AFDC recipients

Even before the 1996 overhaul of the U.S. welfare system, a number of states had ended the practice of paying extra benefits to families who have additional children while receiving welfare. Proponents believe that this reform can reduce births to recipients, however many worry that it may encourage women to obtain abortions. Using a sample of unmarried AFDC recipients from the NLSY, we estimate a bivariate probit model of pregnancy and, conditional on becoming pregnant, the probability of abortion. Our results lend some support for the proposition that reducing incremental AFDC benefits will decrease pregnancies without increasing abortions. Received: 16 April 1998/Accepted: 11 March 1999     

Occupancy numbers for dynamic heterogeneous populations: Estimate of particles lifetimes

A dynamic model of a heterogeneous population is studied. Particles belonging to a population are divided, at every time t, into a finite number of classes according to their types and the partition changes over time. The role of the occupancy numbers, namely the cardinality of each class, is highlighted. The relationship between the stochastic process of occupancy numbers and the process of particle types is analyzed. The main goal of this paper is the estimation of the lifetime of each particle at a given time t, when the observed data are the history of the process of the number of dead particles up to t. Furthermore, a discrete time approximation of the filter is given.     

On a multiple endpoints testing problem

In a clinical trial comparing drug with placebo, where there are multiple primary endpoints, we consider testing problems where an efficacious drug effect can be claimed only if statistical significance is demonstrated at the nominal level for all endpoints. Under the assumption that the data are multivariate normal, the multiple endpoint-testing problem is formulated. The usual testing procedure involves testing each endpoint separately at the same significance level using two-sample t-tests, and claiming drug efficacy only if each t-statistic is significant. In this paper we investigate properties of this procedure. We show that it is identical to both an intersection union test and the likelihood ratio test. A simple expression for the p-value is given. The level and power function are studied; it is shown that the test may be conservative and that it is biased. Computable bounds for the power function are established.     

轻钢与秸秆复合板结构的住宅经济性分析

以中国建设社会主义新农村及全面建设小康社会的国家政策导向为背景,结合西部地区村镇住宅的实际情况,分析村镇住宅的现状,提出基于轻钢与秸秆复合板结构的村镇小康住宅体系,并从定性及定量两个方面进行分析,尤其从结构自重、建筑使用面积、施工周期及建筑节能四个方面与传统村镇住宅体系进行经济性比较,分析认为:轻钢与秸秆复合板结构的小康村镇住宅的综合经济性有较大优势。     

Birth order effects on young students’ academic achievement

We examine birth order effects on academic achievement for ten-year-old students using data for the entire population of fifth graders in Norway 2007/2008. The analysis thus adds to a thin empirical literature focusing on birth order effects among young children. We find that being firstborn confers a significant advantage in families with two, three and four children. The analysis makes two other contributions. First, we provide evidence that unless mother's age at childbirth is included among the control variables, only small and imprecise birth order effects are revealed in families with low socioeconomic status. Second, we provide some evidence that the birth order effects differ across families with highly educated and less educated mothers, which lend support to the resource dilution model over the confluence model.     

Are people in the South less intelligent than in the North? IQ and the North–South disparity in Italy

Socioeconomic disparity between North and South Italy has been recently explained by Lynn (2010) as the result of a lower intelligence quotient (IQ) of the Southern population. The present article discusses the procedure followed by Lynn, supplementing his data with new information on school assessments and per head regional income. Genetic North–South differences are then discussed on the basis of the most recent literature on the subject. The results do not confirm the suggested IQ-economy causal link.