湖南省农业生态与农业经济耦合性测度

[目的]考察湖南省近9年来农业生态与农业经济系统耦合发展现状,探究二者发展过程中的规律,以期找出二者协调发展模式,并为湖南省农业生态环境保护、农业经济发展提供决策依据。[方法]运用耦合协调度模型,基于熵权法为各指标进行客观确定权重,结合2007~2015年湖南省农业生态与农业经济发展的相关数据,确定农业生态与农业经济的耦合匹配分析模型,采用熵值赋权法确定各项指标的权重,构建农业生态—农业经济耦合协调评价指标体系。[结果]研究结果表明,2007~2015年湖南省农业生态与农业经济的耦合协调发展基本稳定,耦合度值均在0.9以上,二者呈协调发展趋势。其中,2014年和2015年二者的耦合度较高,分别为0.975 3和0.984 3,说明湖南省在这两年的农业生态与农业经济的协调性好,农业经济与农业生态能够相互有效促进彼此的发展。同时,仍需时刻关注生态环境的承载力,降低对自然资源的无序攫取,实现经济的可持续发展。     

Risk-managed industry momentum and momentum crashes

This paper investigates Barroso and Santa-Clara’s [J. Financ. Econ., 2008, 116, 111–120] risk-managed momentum strategy in an industry momentum setting. We investigate several traditional momentum strategies including that recently proposed by Novy-Marx [J. Financ. Econ., 2012, 103, 429–453]. We moreover examine the impact of different variance forecast horizons on average pay-offs and also Daniel and Moskowitz’s [J. Financ. Econ., 2016, 122, 221–247] optionality effects. Our results show in general that neither plain industry momentum strategies nor the risk-managed industry momentum strategies are subject to optionality effects, implying that these strategies have no time-varying beta. Moreover, the benefits of risk management are robust across volatility estimators, momentum strategies and subsamples. Finally, the ‘echo effect’ in industries is not robust in subsamples as the strategy works only during the most recent subsample.     

External regulation,independent director attendance,and governance effects

In this study we examine how the regulation of director attendance disciplines directors’ behavior, and consider the governance effect of such regulations. This examination exploits the differences between the requirements for director attendance at board meetings enacted by the Shanghai Stock Exchange (SHSE) and by the Shenzhen Stock Exchange (SZSE). Using a difference-in-differences model with a sample of A-share listed firms from 2006 to 2017, we document that the rate of meeting attendance by independent directors who serve with firms listed on the SHSE (SHIDs) has increased significantly since the exchange’s enforcement of the regulation on attendance. This positive effect has been more pronounced for independent directors with legal backgrounds. Further investigations find that the regulation of attendance plays a corporate governance role through the mechanism of enhanced monitoring. The attendance regulation increases the SHIDs likelihood of casting dissenting votes, and it leads to both better accounting performance and higher firm value. In addition, SHIDs are more likely to depart from firms listed on the SHSE, and to transfer their directorships to firms listed on the SZSE, which has a less constraining attendance requirement. Our findings provide evidence of how external regulation shapes director attendance and voting behavior in emerging markets.     

Product line transformation,foreign sales,and firm value: Evidence from COVID-19 pandemic governance in urban China

Using a sample of Chinese firms, we examine stock market reaction to firms that announce a change in their product lines to those related to COVID-19 management (medical masks and ventilators, among others). We find the market reacts positively to the announcements. In addition, when a firm ordinarily has a large share of export sales, the stock market reaction is more salient, indicating that export sales provide a certification effect that positively signals investors. Additional analysis on moderating effects suggest that, conditional on foreign sales, prior experience with medical product lines or less uncertainty about supply availability enhances the cumulative announcement returns (CARs), while the adverse impact of firm size on CAR magnifies.     

森林食品产业减贫的作用机理及效应分析

首先,介绍森林食品产业减贫的作用机理,主要包括解决资源落后与发展滞后的矛盾;促进贫困地区收入增长;注重多方交流互动。其次,将森林食品产业的减贫效应分为社会减贫效应、经济减贫效应、生态减贫效应这3个部分。最后,提出加强基础设施建设与品牌宣传;增加产业联动效应;持续带动地区增收等建议,以期为政府相关部门制定政策提供决策依据。     

承接金融服务外包对中国就业的影响

研究以金融行业外包服务数据为样本,沿直接与间接两种影响渠道,分析承接金融服务外包对我国就业数量与就业结构的影响,对就业数量变动的流向与趋势进行测算,深入到了劳动力就业质量层面。实证结果表明,承接金融服务外包可以扩大第三产业的相对就业比重,改善知识结构,有利于就业结构与产业结构之间的平衡。但不熟练工人的金融外包业准入将受到限制,加深了他们的就业困境。如何借此机遇将大量低技术劳工培训成合格人才将成为一个严峻的挑战。研究还提出了针对这一新产业形态未来发展的总结与展望。     

省域尺度下不同时序景观指数集与粒度效应分析

[目的]景观格局变化是景观生态学中的热点问题。研究省域尺度下不同时序景观指数的粒度效应、选取计算景观指数所需的适宜粒度范围并筛选出代表性景观指数集对分析景观格局变化具有重要意义。[方法]以安徽省土地覆被为研究对象,以2000年、2005年、2010年的Landsat TM遥感影像为主要数据源,采用土地利用转移矩阵对安徽省土地覆被的转移数量与方向进行研究;通过设置不同的栅格大小研究景观指数的粒度效应并选取合适的粒度范围;基于相关性分析、因子分析与敏感性分析,筛选出代表性景观指数集。[结果](1) 2000—2010年安徽省的土地覆被始终以耕地为主,其次是林地与人工表面;人工表面的增加是建立在耕地面积减少基础之上的,在10年间共有超过3 200km2的耕地转化为人工表面;(2)景观指数存在粒度效应,粒度变化会对景观指数的计算结果产生影响;省域尺度下计算景观指数所需的合适粒度范围为100～125m;(3)研究安徽省景观格局变化的代表性景观指数有4个,分别为最大斑块指数、景观形状指数、平均斑块面积、香农多样性指数。[结论]计算安徽省景观指数的适宜粒度范围为100～125m,安徽省的代表性景观指数集为最大斑块指数、景观形状指数、平均斑块面积、香农多样性指数,为进一步研究景观格局变化及驱动机制提供了依据。     

The dynamic role of small- and medium-sized multinationals in global production networks: Norwegian maritime firms in the Greater Shanghai Region in China

This article examines the role of small- and medium-sized multinational enterprises (MNEs) in the dynamic development of global production networks (GPNs) in the maritime industry. It studies the dynamism between subsidiaries of Norwegian maritime firms and regional actors and institutions in the Greater Shanghai Region of China from the perspectives of the subsidiaries. It argues that strategic coupling, recoupling and decoupling are partly the results of regional selection mechanisms. However, in the cases where the subsidiaries are embedded within the host region, the strategies and behaviour of MNEs are of decisive importance for the dynamic development of GPNs.     

基于效应的随机灰规划模型和应用

为了解决同时含有随机因素和灰色因素的不确定规划问题,通过结合区间灰数所属区间两个端点的随机性,给出随机区间灰数和随机区间灰函数的定义,提出了随机灰规划模型。通过综合效应函数理论用随机变量期望值和方差综合量化表示灰数所属区间的两个端点值。应用该理论对综合量化后的两个端点值继续进行综合量化,从而将随机灰规划转化为确定型规划问题。应用遗传算法进行求解。通过综合效应函数的理念,综合随机变量的期望和方差,同时综合区间灰数的区间因素,将随机灰规划数学模型转化为确定型规划模型即基于效应的随机灰规划模型。通过选取不同的综合效应函数,得到了关于不同决策意识下的随机灰规划的最优解。这个方法可为决策者进行不确定决策提供参考。     

宁夏农业科技园区专项计划项目实施情况及效果分析

农业科技园区专项项目是围绕影响农业产业化关键技术开展研究攻关，把具有市场开发前景的先进适用技术应用于产业化经营上而设立的科技研发项目。研究选取了2014-2016年列入宁夏自治区重点研发计划农业科技园区专项的69 个项目，从项目的执行情况、完成效果、组织管理以及经济和社会效益等方面进行绩效评价，并提出了存在的问题和建议。