Estimating the Size of Street-Dwelling Populations Using Mark-Resighting Counts

Mark-resighting constitutes an advanced technology for estimating animal abundance. Joint hypergeometric maximum likelihood, Minta-Mangel and Bowden estimators are usually adopted with mark-resighting data. In presence of any tendency of animals to aggregate into groups, the Bowden estimator is the sole reliable method, providing that marks are quite evenly distributed among groups. In some cetacean surveys, marking disturbances are avoided through natural marking. Natural marking with Bowden criterion is used to estimate the abundance of street-dwelling populations. The marked individuals are persons identified and recorded in the initial part of the survey and recognizable in subsequent occasions. A simulation helps determine the performance of the Bowden estimator under a wide set of situations, taking into account key features of street-dwelling populations. When marked individuals are evenly distributed among groups, the strategy is efficient.     

上海与纽约黄金期货价格联动关系实证分析

为研究国内外期货黄金价格之间的关联性,对2011～ 2012年间的纽约期金日收盘价格和上海期金开盘价格进行协整检验、因果检验,建立误差修正模型,进行脉冲响应分析和方差分解研究.结果表明：上海黄金期货市场与纽约黄金期货市场价格之间存在长期均衡的关系.上海期货价格受到纽约期货市场价格的影响幅度更大,时间间隔更短.     

安徽省市域经济增长质量动态模糊综合评价——基于改进的AHP-FCE集成模型

基于评价指标提供的信息和运用改进的AHP-FCE集成模型对2002—2011年间安徽省各市经济增长质量进行了动态模糊综合评价。从构建的描述经济增长质量5个维度的指标体系中选取了8个代表性指标,建立模糊关系矩阵并优化生成客观权重,由模糊合成运算得到动态综合评价结果。通过各市经济增长质量动态综合评价值、最大序差和影响因素分析,显示出安徽省市域经济增长质量在10年间的动态变化轨迹和区域性差异,只有个别城市处于经济增长质量的核心区域,更多的城市则处于经济增长质量的＂跳跃＂区域,经济增长质量的各维度发展程度不均衡。     

基于VAR模型的安徽省粮食产量影响因素的实证研究

自然条件、政策环境、经济因素、技术进步等因素都会影响粮食产量。选取安徽省1990-2012年影响粮食生产的7个因素,最初,使用前向逐步回归分析的方法研究发现,对粮食产量影响较大的因素有粮食成灾面积、有效灌溉面积、化肥施用量3个变量。其次,Johansen协整检验阐释了这3个变量与粮食总产量之间的关系,并构造脉冲响应函数及进行方差分解得出这3个变量对总产量的贡献度为：粮食成灾面积〉化肥施用量〉有效灌溉面积。所以,增强农业工程的防灾减灾效果,提升农田水利基础设施的使用效率,科学控制化肥施用量对提高安徽省粮食综合生产能力具有重大作用。     

国际干散货运输航线间即期与远期市场的关联机制研究

以C3、C5航线FFA交易即期和远期的日数据为研究对象,以向量自回归模型为基础,利用脉冲响应分析和方差分解分析方法,对C3、C5航线的即期与远期市场及其航线间的相关关系进行了实证分析。脉冲响应结果显示,同一航线即期市场的波动会引起远期市场的波动,反之则影响较小;C5航线的波动能迅速传给C3航线,反之则较弱。通过方差分解分析可以发现,即期市场的预测波动大约有50％来源于对应的远期市场但远期市场的预测波动主要取决于远期市场本身;C3航线的预测波动主要取决于本航线,而C5航线的预测波动则有一半来源于C3航线。     

Variance estimation when donor imputation is used to fill in missing values

Donor imputation is frequently used in surveys. However, very few variance estimation methods that take into account donor imputation have been developed in the literature. This is particularly true for surveys with high sampling fractions using nearest donor imputation, often called nearest‐neighbour imputation. In this paper, the authors develop a variance estimator for donor imputation based on the assumption that the imputed estimator of a domain total is approximately unbiased under an imputation model; that is, a model for the variable requiring imputation. Their variance estimator is valid, irrespective of the magnitude of the sampling fractions and the complexity of the donor imputation method, provided that the imputation model mean and variance are accurately estimated. They evaluate its performance in a simulation study and show that nonparametric estimation of the model mean and variance via smoothing splines brings robustness with respect to imputation model misspecifications. They also apply their variance estimator to real survey data when nearest‐neighbour imputation has been used to fill in the missing values. The Canadian Journal of Statistics 37: 400–416; 2009 © 2009 Statistical Society of Canada     

Bayesian approach to estimation of intraclass correlation using reference prior

For the balanced variance component model when the intraclass correlation coefficient is of interest, Bayesian analysis is often appropriate. Berger and Bernardo’s (1992a) grouped ordering reference prior approach is used to analyze this model. The reference priors are developed and compared for the posterior inference with real and simulated data. We examine whether the reference priors satisfy the probability-matching criterion. Further, the reference prior is shown to be good in the sense of correct frequentist coverage probability of the posterior quantile.     

Anova and minque type of estimators for the one-way random effects model

The one-way random effects model with unequal variances and unequal sample sizes is considered. Estimation of the variances, variance of a single observation (total variance), and the standard error of the unweighted mean are considered. Precision of the Analysis of Variance and Unweighted Sums of Squares type of estimators and the Minimum Norm Quadratic Unbiased Estimators with a priori weights are examined.     

A generalized improvement procedure for variance bounds for minimum variance unbiased estimator in inverse sampling

New bounds are obtained for the variance of the minimum variance unbiased estimator of p i n inverse sampling. A generalized procedure for further improving the bounds is also discussed.     

1973 Section Officers,Committees and Association Representatives

The occurrence of missing data cells precludes a universally correct procedure for performing an analysis of variance. This is illustrated by the use of two computer routines to analyze a 2 × 3 factorial experiment with one missing cell. One of these routines does, however, provide information that may enhance the usefulness of the associated results.