国外人口普查：从全面调查到行政记录

人口普查的传统方法是全面调查。这种方法的缺陷是成本高、居民负担重和数据质量不高。为了改变这个局面．一些国家正在尝试或者是已经把行政记录作为人口普查数据来源。     

Nonparametric Bayes and empirical Bayes estimation of the population median,with application in finite-population sampling

ABSTRACT

Nonparametric Bayes and empirical Bayes estimators of the population median are provided under Dirichlet process priors. The finite-population sampling is used to estimate the finite-population median under Dirichlet process priors. The asymptotic properties of the estimators are obtained from a frequentist perspective.     

Selection of Prior for the Variance Component and Approximations for Posterior Moments in the Fay-Herriot Model

In the Fay-Herriot model, a prior distribution for the variance component allows posterior moments to be approximated with the Laplace method, avoiding computer intensive Monte Carlo Markov chains. The extremely skewed posterior distribution of the variance component results from the asymmetry of the parameter space with variance parameters constrained to be positive. The prior avoids the extreme skewness of the posterior in contrast to the commonly used uniform prior. With this prior, the mean squared error and coverage in the approximate hierarchical Bayes method are satisfactory when used to estimate small area means. Computation time is shorter than with Monte Carlo Markov chains. The approximations give easy interpretations of Bayesian methods and highlight frequentist properties of the parameters.     

A population size estimate of the finless porpoise,Neophocaena phocaenoides, from aerial sighting surveys in Ariake Sound and Tachibana Bay, Japan

We estimated the population size of the finless porpoise (Neophocaena phocaenoides) in Ariake Sound and Tachibana Bay of western Kyushu, southwestern Japan, from aerial sighting surveys using line transect methods. All 12 surveys were conducted from May 1993 to May 1994 (8 in Ariake Sound and 4 in Tachibana Bay). In addition to these, 14 surveys were also carried out to obtain information on porpoise occurrence in Tachibana Bay (5 surveys) and in neighboring Sumo Nada (5) and Yatsushiro Sound (4). In Ariake Sound, 225 porpoise groups (369 animals) were detected during all flights totalling 1,694.4 km. In Tachibana Bay, a total of 997.8 km was surveyed and 55 groups (290 animals) were sighted. However, no sightings were recorded in Sumo Nada (distance searched = 148.7 km) and Yatsushiro Sound (208.4 km). In Ariake Sound, few sightings were recorded from waters shallower than 5 m in depth. In Tachibana Bay all animals were detected from waters of less than 50 m depth. The population size was estimated as 1,983 animals in Ariake Sound (95% CI = 1,382-2,847), 1,110 in Tachibana Bay (95% CI = 642-1,920), and 3,093 in the 2 waters (1.3 individuals/km², 95% CI = 2,278-4,201).