Spatiotemporal Modeling of Asian Citrus Canker Risks: Implications for Insurance and Indemnification Fund Models

Asiatic citrus canker is a disease that poses a significant hazard to commercial citrus production. This article examines spatiotemporal models of the risks of citrus canker transmission. Models evaluate risks and are used to price annual contracts, which would pay producers a prespecified indemnity in the event that their grove is found to be infected with canker. Implications for risk management policy are discussed.     

矿区地质条件对农村居民点整理模式选取的影响分析——以山东省肥城煤矿区为例

研究目的：通过分析不同农村居民点整理模式集中分布区域的地质条件,找出影响整理模式选取的各种地质环境。研究方法：综合分析法、归纳法。研究结论：地质条件是矿区选取农村居民点整理模式的根本依据。近年来,中国农村居民点整理范围不断扩大,但对复杂地质环境区域,尤其是地质环境复杂的矿区的农村居民点整理研究还比较少,应加大对特殊地质条件下农村居民点整理的研究。     

The tragedy of the commons: property rights and markets as solutions to resource and environmental problems

In one way or another, all environmental and natural resource problems associated with overexploitation or under provision of public goods, arise from incompletely defined and enforced property rights. As a result private decision makers do not consider or internalize social benefits and costs in their production or investment actions. The gap between private and social net returns results in externalities – harmful effects on third parties: overfishing, excessive air pollution, unwarranted extraction or diversion of ground or surface water, extreme depletion of oil and gas reservoirs. These situations are all examples of the 'The Tragedy of the Commons'. In this paper, I consider options for mitigating the losses of open access: common or group property regimes, government tax and regulation policy, more formal private property rights. I briefly summarize the problems and advantages of each option and describe why there has been move toward rights-based instruments in recent years: ITQ (individual transferable quotas), tradable emission permits, and private water rights. Introductions to the papers in the special issue follow.     

Ranking Crop Yield Models: A Comment

This comment discusses key specification issues that may have affected the performance and, therefore, the ranking of parametric models that were compared in a recent AJAE article. A procedure to obtain the most flexible parametric model specification possible, given the particular probability distribution function on which the model is based is presented. These specifications also allow for standardized and, therefore, more valid comparisons across parametric models that are based on different probability distributions. Finally, the comment cautions against generalization of the rankings in that AJAE article and recommends that these more flexible specifications be adopted in future comparisons and applications.     

省级主体功能区规划实施评价

主体功能区规划是指导国土空间开发的宏观和战略性规划。随着规划进入实施阶段,实施评价研究亟待展开。以省级主体功能区规划为对象设计了总体框架,探讨了结果—过程评价相结合的规划实施评价指标设计思路,分别从规划目标实现程度、分区功能落实情况、规划实施保障机制和规划社会影响评价4个方面,选择31个具有代表性的指标确定了规划实施评价的指标体系,并对主体功能区规划实施评价指标权重确定、指标标准化、评价方法等进行了探讨。     

不同农地经营权流转方式的空间依赖性分析

研究目的:探究不同农地经营权流转方式的空间依赖性。研究方法:基于2015年省级截面数据,对转包、出租和入股三种农地经营权流转方式进行全局与局部空间自相关检验,结合空间计量模型进一步探讨不同流转方式下空间依赖的机制及强度。研究结果:(1)全局层面,经营权流转空间收敛特征显著,转包和出租方式表现为空间正自相关,入股方式则呈现随机分布特征;(2)局部层面,"高—高"聚集和"低—低"聚集为各省区主要空间聚集模式,热点区域主要分布在中部和东部地区,冷点区域主要分布于中部、东部和西部地区;同一省区、不同流转方式下,空间聚集模式存在显著差异;(3)针对不同流转方式,基于传统最小二乘法回归的残差项检验均拒绝无空间依赖关系的原假设;进一步使用SLM和SARAR空间计量模型展开分析,结果表明,整体层面的经营权流转、转包以及出租等流转方式均存在显著的空间依赖性。研究结论:不同农地流转方式具有经济行为上的空间规律,不应简单地视流转为一个抽象概念,应将具体的流转行为从空间依赖和空间异质层面纳入政策制定过程,更为精准地制定具有区域化与省域化特征的农地流转政策。     

Aspects of statistical analysis in DEA-type frontier models

In Grosskopf (1995) and Banker (1995) different approaches and problems of statistical inference in DEA frontier models are presented. This paper focuses on the basic characteristics of DEA models from a statistical point of view. It arose from comments and discussions on both papers above. The framework of DEA models is deterministic (all the observed points lie on the same side of the frontier), nevertheless a stochastic model can be constructed once a data generating process is defined. So statistical analysis may be performed and sampling properties of DEA estimators can be established. However, practical statistical inference (such as test of hypothesis, confidence intervals) still needs artifacts like the bootstrap to be performed. A consistent bootstrap relies also on a clear definition of the data generating proces and on a consistent estimator of it: The approach of Simar and Wilson (1995) is described. Finally, some trails are proposed for introducing stochastic noise in DEA models, in the spirit of the Kneip-Simar (1995) approach.     

北京文化创意产业集聚区建设研究

近年来,北京文化创意产业发展态势良好,成效显著,形成了一批特色鲜明的文化创意产业集聚区。本文在介绍北京文化创意产业集聚区总体发展情况的基础上,着重分析总结出北京文化创意产业集聚区建设发展的四种典型模式,并提出了进一步推进文化创意产业集聚区发展的对策与思路。     

Empirical Bayes analysis of log-linear models for a generalized finite stationary Markov chain

This article presents the empirical Bayes method for estimation of the transition probabilities of a generalized finite stationary Markov chain whose ith state is a multi-way contingency table. We use a log-linear model to describe the relationship between factors in each state. The prior knowledge about the main effects and interactions will be described by a conjugate prior. Following the Bayesian paradigm, the Bayes and empirical Bayes estimators relative to various loss functions are obtained. These procedures are illustrated by a real example. Finally, asymptotic normality of the empirical Bayes estimators are established.