就业结构调整对水库移民土地流转的影响研究*——以南水北调中线工程移民为例

[目的]为促进水库移民的生计恢复及转型,探寻就业结构和土地流转间的交互机制,分析两者间耦合作用对当前移民安置模式及政策的影响。[方法]文章从移民就业结构变迁出发,通过超边际理论构建了安置区移民土地的流转机制模型,推演了从业决策对土地流转行为的影响路径,并运用南水北调农业安置移民数据进行实证检验。[结果]大面积转出土地是移民搬迁后土地处置的主要行为,移民中土地转入户有所增加,但土地集中度却有所减少。移民非农就业较搬迁前有明显上升,并有向当地兼业转移的趋势,但与土地流转间并不互为因果,农村社保还难以弱化其对土地养老的依赖。劳动力数量、非农就业时间、非农收入占比、土地政策等对移民土地流转行为和规模均有显著影响,而外出就业前景和地租水平在促进土地流转行为的同时,却不一定能增加土地流转面积。[结论]移民外迁中可以采用无土安置代替农业安置,推动移民土地流转的关键在于技能培训、政策保障和地租补贴,简单的就业推荐和土地权属划分的作用有限。而对于移民中的农业大户,则需在满足土地转入面积的基础上,保障其在安置区的各项土地权益。     

Why has China’s vertical specialization declined?

Vertical specialization (VS) is quantified by the VS share, which measures the average import content per dollar of exports. A characteristic of China’s export trade is its strong dependence on assembly and processing activities. To take proper account of this, China’s VS shares should explicitly distinguish processing export production from other production. We estimate China’s annual VS shares from 2000 to 2012—the latest year for which a special input–output table is available that makes such an explicit distinction. We find that VS shares increased from 2000 to 2004 and subsequently started to decrease. To explore why it has declined, we introduce a new structural decomposition approach. We find that the decrease of the VS share appears to have been driven mainly by the substitution of imported intermediates by domestic products. This occurred in particular in the production of exports, which implies an upgrading of China’s position in global value chains.     

Business Ties and Information Advantage: Evidence from Mutual Fund Trading

This article examines whether ties to portfolio firms’ management via pension business relationships provide mutual funds with an informational advantage. Funds become related to portfolio companies when fund families serve as trustees for firms’ employee pension plans. Selling by related funds is more likely to be motivated by an information advantage than their buying, because the latter is heavily influenced by the desire to secure pension inflows. We find that stocks with larger net sales by related funds experience lower future returns. Information appears related to firm fundamentals, as the return predictability of related funds’ selling concentrates in stocks with negative future earnings surprises. Consistent with an information‐based explanation, the predictive power of related funds’ selling for future returns is more pronounced when information uncertainty about the stock is higher. Our results contribute to a growing literature that shows the sources of informed trading by institutions.     

制造业产业集聚如何影响生态环境

以产业集聚外部性效应为视角,利用2010-2016年天津市南港工业园、逸仙科学工业园、现代产业园与微电子工业园4个制造业产业园区面板数据,实证分析产业集聚与生态环境的双重效应关系,揭示其内在作用机制。结果表明：制造业产业集聚对生态环境存在正负两种外部性效应,具体作用取决于绿色技术创新与外商直接投资两个中介变量。当产业集聚水平较低时,绿色技术创新在制造业产业集聚对生态环境的影响关系中作用不明显。外商直接投资在制造业产业集聚与生态环境关系中起中介作用,即制造业产业集聚会加大外商直接投资规模,对生态环境产生消极影响;当产业集聚水平较高时,绿色技术创新在制造业产业集聚与生态环境的关系中起中介作用,即制造业产业集聚提高了绿色技术创新水平,对生态环境具有积极影响。外商直接投资在制造业产业集聚与生态环境关系中的作用不显著。     

科技创新与绿色治理协调效应评价及动态关系研究

基于2004-2016年中国内地30个省市面板数据,采用耦合协调模型和PVAR模型,实证检验科技创新与绿色治理的协调效应及动态关系。结果显示：2004-2016年全国各省市科技创新与绿色治理的协调水平偏低,并且由东向西的区域阶梯递减特征显著,多数省市科技创新滞后于绿色治理发展,协调等级处于濒临失调水平以下;东部地区科技创新与绿色治理之间存在双向因果关系,科技创新对绿色治理的影响不显著,长期看呈现为负向冲击效应,绿色治理对科技创新呈现出显著正向、持续影响;东北地区科技创新与绿色治理存在单向因果关系,科技创新对绿色治理的冲击效应不显著,绿色治理对科技创新呈现出显著正向、持续影响;中部和西部地区科技创新与绿色治理不存在因果关系,绿色治理对科技创新的冲击作用具有相似性,但科技创新对绿色治理的冲击效应存在较大差异。     

数字化转型、多元化经营与企业绩效

本文以既有研究为基础,考察了企业数字化转型如何改变多元化经营的绩效影响。文章采用2007—2020年中国A股上市公司数据,运用面板二值选择模型、模糊双重差分模型以及面板固定效应模型进行实证检验,同时使用传统多期双重差分模型进行对照。研究结果表明：数字化转型与多元化经营之间具有强大的协同作用。从事实上看,数字化转型能够提高企业开展多元化经营的概率,也能够提升企业多元化经营水平。从机理上看,数字化转型能够提升企业多元化经营的预期收益,并且这一效果在劳动密集型产业中最为明显。本研究综合运用资产专用性、范围经济等理论探究了数字化转型与多元化经营之间的联动效果,开创了对于多元化经营对企业绩效影响的新型研究视角。     

基于灰熵模型的大型工程项目供应商评价研究

针对大型工程的特点,建立供应商综合评价指标体系;将灰熵理论应用于大型工程供应商的评价,建立了基于灰熵理论的供应商综合评价模型。通过实例分析表明,灰熵模型对于大型工程项目供应商的评价客观有效,能够为大型工程供应商的选择提供科学依据。     

Crowdsourcing-based semantic relation recognition for natural language questions over RDF data

ABSTRACT

Natural language query systems over RDF data need to rely on the semantic relations in query. First, we propose the new crowdsourcing model that used to produce semantic relations dataset. The model not only inherits completeness of the iterative model and accuracy of the parallel model, but also saves human resources. Second, we mine the rules of semantic relation recognition from the correlations between dependency structures and semantic relations. Third, we propose an algorithm of semantic relation recognition for natural language query over RDF data, and experiments demonstrate that it can recognize more semantic relations than existing methods.     

通胀目标制与汇率目标制不能共存吗

基于汇率传递的风险溢价渠道，本文将我国利率调控通胀、外汇储备对冲干预汇率纳入新凯恩斯政策模型，构建双目标双工具政策分析框架，比较泰勒规则与双目标双工具规则下通胀目标与汇率目标共存的经济机制与效应。本文模拟显示：（1）双目标双工具政策框架下通胀目标与汇率目标能够共存，此时通过影响汇率风险溢价来盯住汇率不影响通胀；而单工具政策下两目标无法共存，此时降低国内资产的收益率盯住汇率会刺激居民的消费行为引起通胀。（2）国际资本冲击下，双目标双工具政策在固定汇率的同时能保证经济稳定；而当贸易条件恶化时，选择完全浮动汇率制度最优。央行政策损失分析进一步验证了以上结论。（3）随着金融市场化改革深入，外汇储备稳定汇率的有效性将下降，冲销成本会大幅提升。资本账户开放下，双目标双工具政策仍是央行抵御外部资本冲击的首选政策；但是汇率市场化后，通胀目标制与双目标双工具政策效果基本无差异。本文结论的启示是：面对国际资本，需必要的汇率管制；但是面对贸易冲击，可适度提升汇率弹性来减少冲击对产出和通胀的影响。     

涉农贷款中新担保措施的合法性及有效性分析

为防范涉农贷款违约风险,部分农村信用联社积极探索,创新出债权文书公证方式、以人身险保险金担保债权等担保方式,以确保债权得到切实维护.这些新担保方式一定程度上增加了农村贷款供给,但存在法律风险.本文着重对这些新措施、新方法的合法性及有效性进行了探讨.