产业融合对中国装备制造业创新效率的影响:结构嵌入的调节作用

从理论和实证两个方面探讨了产业融合对中国装备制造业创新效率的影响，以及网络中心性和网络异质性对二者关系的调节作用。基于2006—2015年省际装备制造7个子行业面板数据，采用ISCNFI指数测度模型和基于产出距离函数的超越对数前沿分析方法，分别测度装备制造业产业融合程度及创新效率变化情况，进而利用面板回归模型对理论假设进行实证检验。结果显示：产业融合程度与中国装备制造业创新效率存在倒“U”型曲线关系，即随着产业融合程度提升，中国装备制造业创新效率呈现出先上升后下降的变化趋势；网络中心性强化了产业融合对装备制造业创新效率的提升作用，而网络异质性削弱了产业融合对装备制造业创新效率的提升作用。     

An inexact l2-norm penalty method for cardinality constrained portfolio optimization

Abstract

We analyze and solve a single-period portfolio optimization problem with non-convex constraints, which address practical concerns of investment such as the active share weights of sectors and the number of stocks held in a portfolio. We reformulate the problem to simplify the computation and propose an inexact l₂-norm penalty method to solve the problem.     

多创新方法集成与融合应用的LCUE矩阵法研究及实施

在日益复杂的产品需求和生产环境下，企业面临的生产难题也更加复杂，如何科学系统地使用创新方法解决企业生产难题，是长期困扰企业的问题。研究多个创新方法集成与融合应用概念模型，构建以企业生产难题为导向的多创新方法集成与融合应用理论体系，并基于多创新方法集成与融合应用过程，提出从多个维度指导企业实施多创新方法集成与融合应用的“LCUE矩阵法”。最后，结合某空调装配企业生产实际，以价值流方法为模板，基于LCUE矩阵实施多创新方法集成与融合应用，有效解决了企业生产难题，验证了多创新方法集成与融合应用及LCUE矩阵法的可行性。     

The Effect of Foreign Entry Regulation on Downstream Productivity: Microeconomic Evidence from China*

We examine the cross‐industry influence of foreign entry regulation (based on a novel measure) on the productivity outcomes of downstream firms through input–output linkages in China. In contrast to the significant liberalization of the manufacturing sector, restrictions on the service sector remained stringent over the period 1997–2007. We find a powerful depressant effect of foreign entry barriers imposed on the upstream manufacturing and service industries on the productivity of downstream manufacturers, and this effect depends on a number of industry‐ and firm‐specific features. Our research calls for further investment liberalization (particularly in the service sector) in China.     

A cost-effectiveness analysis of revaccination and catch-up strategies with the 23-valent pneumococcal polysaccharide vaccine (PPV23) in older adults in Japan

Objective: In Japan, the National Immunization Program (NIP) includes PPV23 as the primary vaccination for adults and catch-up cohorts. The Japanese Association for Infectious Diseases recommends revaccination for older adults who received primary vaccination ≥5 years earlier. The cost-effectiveness of adding revaccination and/or continuing catch-up vaccination in the NIP was evaluated from the public payer perspective in Japan.

Methods: The Markov model included five health states: no pneumococcal disease, invasive pneumococcal diseases (IPD), non-bacteremic pneumococcal pneumonia (NBPP), post-meningitis sequelae, and death. Cohorts of adults aged 65–95 were followed until age 100 or death: 2014 cohort (aged 65–95, vaccinated: 2014); 2019 cohort (aged 65: 2019); and 2019 catch-up cohort (aged 70–100: 2019, unvaccinated: 2014). Strategies included: (1) vaccinate 2014 and 2019 cohorts; (2) vaccinate 2014 and 2019 cohorts and revaccinate both; (3) strategy 1 and vaccinate 2019 catch-up cohort; (4) strategy 2 and vaccinate 2019 catch-up cohort; and (5) strategy 4 and revaccinate 2019 catch-up cohort. Parameters were retrieved from global and Japanese sources, costs and QALYs discounted at 2%, and incremental cost-effectiveness ratios (ICERs) estimated.

Results: Strategy 1 had the highest number of IPD and NBPP cases, and strategy 5 the lowest. Strategies 3–5 dominated strategy 1 and strategy 2 was cost-effective compared to strategy 1 (ICER: ¥1,622,153 per QALY gained). At a willingness-to-pay threshold of ¥5 million per QALY gained, strategy 2 was cost-effective and strategies 3–5 were cost-saving compared to strategy 1.

Conclusions: Strategies including revaccination, catch-up, or both were cost-effective or cost-saving in comparison to no revaccination and no catch-up. Results can inform future vaccine policies and programs in Japan.     

Do ongoing networks block out new friends? Reconciling the embeddedness constraint dilemma on new alliance partner addition

Research Summary: This study addresses a theoretical dilemma regarding how alliance network constraint (reflected by network cohesion) affects a firm’s alliance formation with new partners. Using a network pluralism approach, we separate a firm’s ego alliance network into two activity‐based networks—an exploratory network and an exploitative network—based on the primary value chain activity involved in each alliance. We argue that the cohesion of exploratory or exploitative networks has an inverted U‐shaped effect on the addition of new partners in the same activity‐based network, and a positive effect on the addition of new partners in the other network. Results based on data from the biotechnology industry largely support our predictions with one exception. Our study contributes to both scholarly understanding of network embeddedness and alliance practice. Managerial Summary: The structure of firms’ ongoing alliance networks may have paradoxical implications for their efforts to search for and form alliance with new partners. That is, when a firm’s alliance partners are tightly connected with each other, the cohesive network tends to both encourage and impede the focal firm to add new partners. We resolve this dilemma by showing that when a firm is deeply entrenched in a cohesive alliance network conducting a certain type of activities (e.g., R&D activities), it may not easily add new R&D alliance partners. However, it may still be able to escape from the cohesive R&D alliance network by seeking new partners conducting other activities (e.g., manufacturing activities).     

股权金融市场、增长方式选择与平衡增长：传统与新兴部门视角*

为探究股权金融市场对增长方式选择和平衡增长的影响，本文基于传统与新兴部门的差异，构建动态理论模型并利用“Simulink”技术进行数值模拟分析。理论分析发现股权金融市场效率对平衡增长具有增长效应且存在门槛条件，效率高于门槛值时股权金融市场发展将提高平衡增长率和创新贡献率。总体上，发展股权金融市场将促进我国平衡增长和增长方式转变，但东、西部地区存在差异，发展股权市场可以加快东部地区创新型增长而对西部地区没有显著作用。     

中国海外耕地投资的区位特征及其影响因素*——基于2000—2016年土地矩阵网络数据

［目的］分析中国海外耕地投资的区位特征及其影响因素，以促进我国海外耕地投资的合理布局，提高农业投资效率。［方法］以2000—2016年中国137宗海外耕地投资项目及其所涉及的35个东道国作为研究样本，运用Spearman相关分析方法，分别以耕地投资面积和耕地投资项目数量作因变量，研究其与各影响因素的相关关系，并用对应分析法进一步探究各东道国的相对优势。［结果］（1）我国海外耕地投资区域集中在东南亚且由周边国家向外扩展，被投资耕地用途多样，投资规模自2004年开始急剧上升，近年来呈下降趋势。（2）我国海外耕地投资以效率寻求型和市场寻求型为主，倾向于资源丰富、与我国距离较近、制度相似、经济关系良好但发展水平不高的国家。（3）根据各地区的比较优势，亚洲国家适合效率寻求型和市场寻求型的企业投资，欧洲和美洲国家适合资源寻求型和战略资产寻求型的企业投资，非洲国家适合资源寻求型、效率寻求型和市场寻求型的企业投资。［结论］中国农业企业应结合企业投资目标和各地区的比较优势，合理选择投资区位，适时转变投资策略与模式，积极防范海外耕地投资过程中的自然风险、政治环境风险和道德风险等，以提高投资效果。     

International trade of GMO-related agricultural products

This paper examines the international trade of a variety of genetically modified (GM) food products over a 27-year period (1984–2011) with data from the United Nations using the tools of social network analysis. The results indicate that each of the different crops have a distinctive pattern of trade that has changed over time due to a number of different factors. Also, trade in agricultural commodities became more diversified over time, dominated less by the United States and other nations central in the trade networks and trade in the individual GM crops was stable over time. Countries maintained their trading partners for specific crops, despite the adoption of the genetically modified varieties. The economic implications of these results are discussed for specific countries.     

地理资本视角下村级多维贫困测度及贫困类型划分*——基于重庆市1 919个市级贫困村调研数据

[目的]精确测度村级多维贫困以及划分贫困类型,是当前提高贫困识别精准度,进一步推进农村精准脱贫的战略需求。[方法]文章基于重庆市1 919个市级贫困村的调研数据,构建地理资本视角下村域多维贫困测度指标体系,并采用多维贫困测度模型、指标贡献度模型和最小方差方法系统揭示了重庆市贫困村多维贫困程度、贫困类型及其空间分布特征。[结果](1)重庆市贫困村多维贫困程度呈两端大中间小的"哑铃状"结构,贫困程度极化特征显著,区域发展具有不平衡性。空间分布上,贫困村多维贫困程度呈从渝东北、渝东南分别向渝西地区逐渐减轻的特征,贫困村多维贫困程度存在明显的地域性差异;(2)重庆市贫困村贫困类型主要分为单资本缺失型、双资本缺失型、三资本缺失型、四资本缺失型4个类型,其占比分别为9.07%、20.27%、66.91%、3.75%,三资本缺失型是最主要的贫困类型。[结论]重庆市贫困村致贫因素复杂多样,需要根据各自的贫困特征,因地制宜地开展差别化的帮扶工作。科学推进精准扶贫战略,力争实现2020年全面脱贫。