A neighbourhood-based classifier for landsat data

A classifier is developed which uses information from all pixels in a neighbourhood to classify the pixel at the center of the neighbourhood. It is not a smoother in that it tries to recognize boundaries. and it makes explieite use of the relative positions of pixels in the neighbourhood. It is based on a geometric probability model for the distribution of the classes in the plane. The neighbourhood-based classifier is shown to outperform linear discriminant analysis on some LANDSAT data.     

农村住户调查县级样本代表性评估方法研究

 全国农村住户调查县级样本在1984年抽选后几未改变,在全国农村住户新一轮样本轮换中对其代表性进行评估非常必要,因此研究开发县级样本代表性评估方法有重要意义。本文利用第二次全国农业普查和县市统计数据,以甘肃省为例,通过分析调查县样本特性、考察调查县的收入分布和地域分布,探索调查县农民收入水平对所在省农民收入水平代表性的评估与调查县调整方法。     

小域估计方法在小品种农作物播种面积统计中的应用

 我国以省级目标总体开展的现行农产量抽样调查,着眼于农作物主要品种的省级推算,而小品种农作物的总体分布比较偏态,往往有效样本量相对不足,不能解决小品种农作物播种面积的推算问题,同时对分县的主要品种农作物播种面积进行的直接推算也不能满足精度要求。现阶段对小品种农作物播种面积的统计方法研究成为农村统计方法制度改革迫切需要研究的课题之一。本文选择了河北省张家口的蔚县,利用小域估计方法对小品种农作物播种面积进行了统计推断,从推断结果看得到了比较好的估计精度。利用蔚县为总体的实际数据进行的抽样仿真分析,从实证的角度阐述了小域估计方法对这一问题的有效性,而且分析结果也表明该方法可以显著提高估计效果。     

遥感辅助的农作物种植面积小域估计方法研究

遥感影像是大数据的一种,利用遥感对农作物播种面积进行估算常采用回归估计量或校准估计量,通常都需要将地面样本数据与遥感分类信息相结合。但对于大多数回归估计量,对省级总体的农作物面积估算只能满足对省级总体的精度要求而不能分解到更小区域,比如县和乡级。本文利用黑龙江省2011年的地面实测样本数据结合遥感分类结果,构建了单元层次的多响应变量的多元回归形式的小域模型,并将小域效应设定为固定形式。这样基于回归估计方法,既可以估算分县的主要作物播种面积,也可以使得各县播种面积估计结果相加就等于回归模型含义下的省级总体的总量估计。对黑龙江省玉米、水稻、大豆分县小域估计结果的精度评价（变异系数C.V）,平均而言均可以满足县级精度要求。本文的结果表明小域估计方法在解决省级总体对全省和分县的农作物种植面积多级估算问题中具有很好的应用。     

中国县级政府间财力差距：1993-2003年

 摘　　要:本文利用1993-2003年中国县级地区的财政数据，借鉴收入分配文献中发展出来的地区子集和收入来源不平等分解法，对县级政府财力差距进行了分析，发现中国县级政府财力差距十分悬殊，且财力不均等存在上升趋势；大部分财力不均等是由组内差异解释的，地区间差距对不均等的贡献相对较小；上级财政转移支付不但没有起到均等县级财力的作用，反而拉大了财力差异，特别是在分税制改革后，转移支付造成了近一半的县级财力差异     

Numerical experiments with the thin plate histospline

The thin plate volume matching and volume smoothing histosplines are described. These histosplines are suitable for estimating densities or incidence rates as a function of position on the plane when data is aggregated by area, for example by county. We give a numerical algorithm for the volume matching histospline and for the volume smoothing histospline using generalized cross validation to estimate the smoothing parameter. Some numerical experiments were performed using synthetic data, population data and SMR's (standardized mortality ratios) aggregated by county over the state of Wisconsin. The method turns out to be not particularly suited for obtaining population density maps where the population density can vary by two orders of magnitude, because the histospline can be negative in     

Empirical Bayes procedures for stabilizing maps of U.S. cancer mortality rates

"The geographic mapping of age-standardized, cause-specific death rates is a powerful tool for identifying possible etiologic factors, because the spatial distribution of mortality risks can be examined for correlations with the spatial distribution of disease-specific risk factors. This article presents a two-stage empirical Bayes procedure for calculating age-standardized cancer death rates, for use in mapping, which are adjusted for the stochasticity of rates in small area populations. Using the adjusted rates helps isolate and identify spatial patterns in the rates. The model is applied to sex-specific data on U.S. county cancer mortality in the white population for 15 cancer sites for three decades: 1950-1959, 1960-1969, and 1970-1979. Selected results are presented as maps of county death rates for white males."     

基本公共服务、财政分权与县域经济发展

本文以经济增长、产业结构升级、城乡收入收敛为县域经济发展的主要衡量指标,同时在考虑地区异质性特征的基础上,实证研究基本公共服务和财政分权对县域经济发展的影响。基于河南省108个县2005-2015年面板数据,使用动态空间计量模型及面板数据模型的实证结果显示：从整体上看,基本公共服务水平提升与财政分权有助于县域经济发展;从按财政属性进行县域分类的视角看,上述支撑作用主要表现在不具有特殊财政属性的普通县层面;从按经济水平分类视角看,这种支撑作用主要作用于经济基础好的中心县与经济落后的农区县;从按地理位置分类视角看,临近市辖区的县更好的发挥了上述支撑作用,形成了依托市辖区发展的“溢出效应”。     

南水北调中线工程库区移民劳动力流动状况分析——基于湖北省陨县、丹江口市和河南省淅川县的调查

基于南水北调中线工程经过的湖北省陨县、丹江口市和河南省淅川县的入户调查数据,分析了南水北调中线工程库区移民劳动力的流动状况,包括劳动力的流动模式、形态和方式、流动区域和产业特征、时代分布、年龄构成以及不外出的原因,并同中国农村劳动力流动的整体状况进行了比较,得到如下结论：接受调查的家庭由于地处农村,生育孩子多,除青壮年劳动力外出务工外,老人和孩子均在家,没有外出务工的占大多数;外出务工的绝大部分是青壮年劳动力;广东作为中国改革开放的前沿,吸引了大量的库区劳动力;南水北调中线工程库区居民的本土意识依然很浓厚;南水北调中线工程库区居民外出以从事体力劳动和非技能性劳动为主。根据上述结论,就南水北调中线工程移民安置问题提出了一些建议。     

中国地区经济发展不平衡及影响因素研究——基于夜间灯光数据

本文以全球夜间灯光数据为参照，分别从地级和县级行政区层面研究了1992-2016年我国地区经济发展不平衡的演化及其影响因素。受地级和县级人均GDP数据可得性和准确性的限制，首先利用省级人均GDP与灯光亮度关系估算地级和县级的经济产出水平。基于地级和县级经济产出水平，测算了地区经济差异指数、泰尔指数和阿特金森指数，证实了各省份、全国及四大地区均呈现库兹涅茨倒“U”曲线。对泰尔指数进行四大地区分解，发现了四大地区间的经济差异是我国地区经济不平衡的主要根源。地区经济发展不平衡的影响因素研究再次证实库兹涅茨曲线的存在，还发现城镇化水平和产业结构变迁与地区经济不平衡之间也存在倒“U”型关系，教育水平的提升与交通基础设施的完善分别扩大和缩小了地区经济的不平衡，但资源禀赋、对外开放度和政府消费与地区经济不平衡的关系并不显著。     

Some New Estimators for Small-Area Means With Application to the Assessment of Farmland Values

Regression models that account for main state effects and nested county effects are considered for the assessment of farmland values. Empirical predictors obtained by replacing the unknown variances in the formulas of the optimal predictors by maximum likelihood estimates are presented. The computations are carried out by simple iterations between two SAS procedures. Estimators for the prediction variances are derived, and a modification to secure the robustness of the predictors is proposed. The procedure is applied to data on nonirrigated cropland in the Corn Belt states and is shown to yield predictors with considerably lower prediction mean squared errors than the survey estimators and other regression-type estimators.     

Robust small area estimation

Small area estimation has received considerable attention in recent years because of growing demand for small area statistics. Basic area‐level and unit‐level models have been studied in the literature to obtain empirical best linear unbiased prediction (EBLUP) estimators of small area means. Although this classical method is useful for estimating the small area means efficiently under normality assumptions, it can be highly influenced by the presence of outliers in the data. In this article, the authors investigate the robustness properties of the classical estimators and propose a resistant method for small area estimation, which is useful for downweighting any influential observations in the data when estimating the model parameters. To estimate the mean squared errors of the robust estimators of small area means, a parametric bootstrap method is adopted here, which is applicable to models with block diagonal covariance structures. Simulations are carried out to study the behaviour of the proposed robust estimators in the presence of outliers, and these estimators are also compared to the EBLUP estimators. Performance of the bootstrap mean squared error estimator is also investigated in the simulation study. The proposed robust method is also applied to some real data to estimate crop areas for counties in Iowa, using farm‐interview data on crop areas and LANDSAT satellite data as auxiliary information. The Canadian Journal of Statistics 37: 381–399; 2009 © 2009 Statistical Society of Canada     

甘肃省县域经济发展水平空间差异分析

甘肃省包括86个县区,受地理位置、气候条件、资源状况、经济基础各种因素的影响,各县区之间的经济发展水平差异显著但又有很多相似之处。为了定量揭示甘肃省县域经济发展水平在空间上的分布现状、差异以及相似性,笔者拟运用多元统计方法对甘肃省县域经济发展水平的空间差异分析     

县域经济与城市化的相关分析

县域经济是指在县域行政区间或其经济空间范围内的经济,包括县、市(县级)、区经济。2004年县域经济在全国经济总量中占55.15%,人口占全国总人口的70.9%,在我国国民经济中占有举足轻重的地位。我国有70%以上的人口生活在县域,可见,县域的城市化是实现中国城市化的基础与关键所在     

Dropping out of university: A statistical analysis of the probability of withdrawal for UK university students

From individual level data for an entire cohort of undergraduate students in the 'old' universities in the UK, we use a binomial probit model to estimate the probability that an individual will 'drop out' of university before the completion of their degree course. We examine the cohort of students enrolling full time for a 3- or 4-year degree in the academic year 1989–1990. We find evidence to support both the hypothesis that the completion of courses by students is influenced by the extent of prior academic preparedness and the hypothesis that social integration at university is important. We also find an influence of unemployment in the county of prior residence, especially for poorer male students. Finally, we draw conclusions regarding the public policy of constructing university performance indicators in this area.     

村民政治参与、民主观念与政府信任

基于2009—2011年"中国乡镇民主与治理调查"数据,探讨了中国村民对四级政府的信任状况,并运用Logistic模型重点研究了村民政治参与和民主观念对政府信任的影响。研究发现:村民对国家、省级、县级、乡镇四级政府的信任感依次下降。村民正式的政治参与对四级政府信任均呈现显著的正向影响,即参与过投票选举的村民对四级政府的信任感越强,这也证实了国内外的大多数研究;非正式的政治参与对国家和省级政府的信任也均呈现显著的正向关系,说明谈论国家大事或政治话题的村民更相信国家和省级政府;民主观念对国家政府的信任有显著的正向影响,但是对县级、乡镇政府的信任有显著的负向影响,即民主观念较强的人对基层政府越不信任。     

A pooled Bayes test of independence for sparse contingency tables from small areas

We study the association between bone mineral density (BMD) and body mass index (BMI) when contingency tables are constructed from the several U.S. counties, where BMD has three levels (normal, osteopenia and osteoporosis) and BMI has four levels (underweight, normal, overweight and obese). We use the Bayes factor (posterior odds divided by prior odds or equivalently the ratio of the marginal likelihoods) to construct the new test. Like the chi-squared test and Fisher's exact test, we have a direct Bayes test which is a standard test using data from each county. In our main contribution, for each county techniques of small area estimation are used to borrow strength across counties and a pooled test of independence of BMD and BMI is obtained using a hierarchical Bayesian model. Our pooled Bayes test is computed by performing a Monte Carlo integration using random samples rather than Gibbs samples. We have seen important differences among the pooled Bayes test, direct Bayes test and the Cressie-Read test that allows for some degree of sparseness, when the degree of evidence against independence is studied. As expected, we also found that the direct Bayes test is sensitive to the prior specifications but the pooled Bayes test is not so sensitive. Moreover, the pooled Bayes test has competitive power properties, and it is superior when the cell counts are small to moderate.     

我国县级城市发展质量综合评价——以江苏省县级市为例

城市是一个有多种要素组成的复合体。为准确把握城市的发展质量,运用系统论的观点进行城市的构成分析,从而对城市发展质量进行评价,其评价的目的在于发展性评价,通过对各被评价城市人口、经济、生活、环境、基础设施及整个系统质量的排序或分类,以及对城市质量系统发展的协调性研究等,使我们便于发现城市化进程中存在的问题与不足,使决策者能从城市化质量不断提高的角度来改变其决策结果,为今后城市发展质量的全面提高、科学的决策提供客观依据。对于我国省辖市发展质量的综合评价,笔者已进行过研究。但对县级市来说,无论其发展质量、发展规…     

农村金融排除的空间差异及其收敛性分析——来自中国1728个县（市）的数据

构建普惠性农村金融体系是实现中国农村经济包容增长及建立和谐社会主义新农村的重要组成部分,但目前鲜有文献分析中国农村金融排除的空间差异及其收敛性的因素。鉴此,采用σ收敛、β收敛和＂俱乐部收敛＂三种分析方法,使用来自中国2006—2009年1 728个县（市）的数据,以金融排除指数（IFE）为衡量指标,对中国农村金融排除收敛性进行分析,并对影响农村金融排除的关键因素进行了条件β收敛的检验。研究表明：中国各个县（市）金融排除总体存在σ收敛并表现出明显的β绝对收敛特征;在控制了地理位置、人均GDP、城镇化比例、受教育水平、城乡收入差距、信息技术、就业率和商业环境后,中国农村地区金融排除表现出条件β收敛;东、中、西三大地区不存在俱乐部收敛,东、西部地区呈现出发散,中部地区表现出收敛。以上结论对中国农村普惠性金融体系建设具有指导意义。     

中国县级政府税收竞争研究

税收竞争是地方政府财政竞争的常见方式。为吸引税基,放松税收征管力度是其主要表现形式。理论模型表明地方政府不同策略行为取决于相对税率的权衡;政府间不同的资本税率弹性导致了实际税率的分化。利用空间计量方法分析了中国县级政府的税收竞争行为,发现相邻县存在显著的策略互补(税收模仿);异质性政府税率存在差异,贫穷县的实际税率要高于富裕县。纠正扭曲的税收征管策略和提升市场保护激励是未来改革关键。