非洲猪瘟疫情对我国肉类价格影响的区域异质性研究

[目的]非洲猪瘟疫情暴发导致猪肉等畜产品市场供需结构性、区域性失衡,进而导致肉类价格大幅波动,不利于畜牧业高质量可持续发展。[方法]文章通过构建覆盖全国30个省（市、区,不含港澳台、西藏）,包括猪牛羊和白条鸡四大肉类价格和非洲猪瘟疫情指数的动态面板数据,运用面板向量自回归模型（PVAR）,研究非洲猪瘟疫情对猪肉等主要肉类价格的冲击和影响在重点、约束、适度发展区和潜力增长区(1)的区域异质性。[结果]（1）非洲猪瘟疫情对不同区域不同肉类价格的影响存在着正负向不趋同的方向性差异,在冲击程度大小和时滞期上均存区域异质性;（2）区域间和区域内不同省份间猪肉等肉类生产流通和供需形势、及非洲猪瘟发生发展程度的差异是非洲猪瘟疫情对这些肉类价格冲击影响异质性产生的主要原因。[结论]非洲猪瘟疫情对肉类价格影响存在较为明显的区域异质性,亟需进一步优化生猪等畜牧产业布局,加快形成区域协同发展格局;健全动物疫病防控体系,建立多方协同联动机制;完善市场风险预警调控机制,加快实现产需顺畅匹配,确保畜产品市场总体平稳运行和畜牧业健康可持续发展。     

土地流转对农民创业的影响研究基于社会资本的调节作用分析

目的 土地细碎化与传统分散式经营一定程度阻碍了农业适度规模经营与农民创业,探索土地流转对农民创业的影响,对加速农业现代化发展、实现农民增收具有重要意义。方法 文章阐释土地流转影响农民创业的机理,并依据陕西、宁夏、山东3省（区）1 947份农户调研数据,运用Probit模型实证检验土地流转对农民创业的影响,同时进一步测度社会资本是否发挥调节作用。结果 （1）转入土地正向促进农民创业基本决策,而转出土地负向抑制农民创业基本决策,显著性水平分别为1%和5%。（2）进一步划分创业类型后显示,转入土地能显著促进农民开展涉农创业,而转出土地能促进农民开展非农创业。（3）社会资本的调节作用显著,具体表现为,整合型社会资本在转入土地影响涉农创业中发挥调节作用,而跨越型社会资本在转出土地影响非农创业中发挥调节作用。结论 因此,建议持续推进土地流转政策的深化改革,确保从土地流转到农民创业的顺利衔接;加强农民创业培训体系建设,考核培训后的效益效果,通过提升培训质量助推农民创业;鼓励农民增强社交意识,灵活运用社会网络获取资源,并通过积极社交打通阶级壁垒、促进信息流动,加速创业的开展。     

The service sector and economic growth: some cross-section evidence

It has often been claimed that a relative expansion of the service sector has a deleterious effect on economic growth. This paper uses cross-section country-level data from three decades –1960s, 1970s and 1980s – to see whether in fact this negative relation is reflected in the data. It is found that the effect is negative or positive depending on how the role of the service sector is measured, but there is a strong case that effect is in fact usually negative.     

Tourists and traditional divers in a common fishing ground

We study socio-ecological models for a fishing ground open to tourists. On Jeju Island, Korea, women traditional divers called “Haenyeo” harvest resources in a common fishing ground. To investigate the impact of introducing tourists on the benefit to the fishing association and the resource level, we examine two models that differ in the way the number of tourists is controlled. In the first model, the fishing association charges an entrance fee to tourists and the level of the fee is chosen to regulate tourist number. In the second, only a part of the fishing ground is made open to tourists, and the fraction of the ground open is chosen to control the tourist number. In both models, the fishing association seeks to maximize its total benefit. Analysis shows that the way the number of tourists increases with the availability of resources strongly influences the distribution of benefits among the fishing ground stakeholders. Finally, we discuss policy implications of our results and how local government can reduce the risk of introducing tourism.     

Restricted maximum likelihood estimation under Eisenhart model Ill

For a balanced two-way mixed model, the maximum likelihood (ML) and restricted ML (REML) estimators of the variance components were obtained and compared under the non-negativity requirements of the variance components by L ee and K apadia (1984). In this note, for a mixed (random blocks) incomplete block model, explicit forms for the REML estimators of variance components are obtained. They are always non-negative and have smaller mean squared error (MSE) than the analysis of variance (AOV) estimators. The asymptotic sampling variances of the maximum likelihood (ML) estimators and the REML estimators are compared and the balanced incomplete block design (BIBD) is considered as a special case. The ML estimators are shown to have smaller asymptotic variances than the REML estimators, but a numerical result in the randomized complete block design (RCBD) demonstrated that the performances of the REML and ML estimators are not much different in the MSE sense.     

Performance lies are hazardous to organizational health

Performance lies arise both from individual and from situational causes, but in this article, the attention is on situational causes. These are generally triggered by loyalty to the coalition, which is expressed through the continued use of performance lies. Because performance lies help create a boundary around the coalition that insulates its activities from top management, performance lies enable members of the coalition to exercise a greater degree of internal control. Naturally, such lies are dysfunctional, resulting in the avoidance of difficult issues and problems and compromising the organization's ability to adapt to a changing environment based on accurate information.     

Mean squared error efficient estimators of the variance components

Summary Pseudo Bayesian estimators for the variance components based on Jeffrey’s Rule are derived for the mixed balanced incomplete block design and are compared with the usual analysis of variance estimators in terms of mean squared error (MSE) efficiency. Numerical results show that Pseudo-Bayesian estimators are more efficient in numerical results.     

企业低碳成长的路径与策略开发

着力于从企业角度探讨实现低碳成长的路径与策略,分析了低碳经济的涵义,提出了企业低碳成长的概念;从个体、组织、经济—社会—环境3个层次的互动作用入手,探讨了企业低碳成长的逻辑,构建了低碳成长的路径框架;依据不同的路径提出了温和型低碳成长、激进型低碳成长、构建低碳成长企业伦理、与企业效益建立链接4类实施策略。