中国服务业显性比较优势测算——基于前向联系增加值出口

基于"前向联系增加值出口"方法,测算了1995-2011年中国服务业细分产业层面及按要素密集度特征分类层面的显性比较优势指数(RCA_F),并同基于"总出口"1的比较优势指数(RCA)进行了比较。研究发现,中国在全球价值链分工中,比较优势集中在资本密集型服务业领域,且实现了比较劣势向比较优势的转变;劳动、知识密集型服务业及健康教育公共服务均尚未取得比较优势,但是有迹象表明三个领域的比较劣势有改善的趋势。与基于前向联系增加值出口核算结果相比,基于总出口核算结果"高估"了劳动密集型产业的比较优势,其中对建筑业和零售贸易两个部门的估计偏差最大;同时,在资本、知识密集型两个领域存在不同程度的"低估"现象。     

Dependency and truncated forms of combinations in multivariate combination-based permutation tests and ordered categorical variables

ABSTRACT

Quite an important problem usually occurs in several multi-dimensional hypotheses testing problems when variables are correlated. In this framework the non-parametric combination (NPC) of a finite number of dependent permutation tests is suitable to cover almost all real situations of practical interest since the dependence relations among partial tests are implicitly captured by the combining procedure itself without the need to specify them [Pesarin F, Salmaso L. Permutation tests for complex data: theory, applications and software. Chichester: Wiley; 2010a]. An open problem related to NPC-based tests is the impact of the dependency structure on combined tests, especially in the presence of categorical variables. This paper’s goal is firstly to investigate the impact of the dependency structure on the possible significance of combined tests in cases of ordered categorical responses using Monte Carlo simulations, then to propose some specific procedures aimed at improving the power of multivariate combination-based permutation tests. The results show that an increasing level of correlation/association among responses negatively affects the power of combination-based multivariate permutation tests. The application of special forms of combination functions based on the truncated product method [Zaykin DV, Zhivotovsky LA, Westfall PH, Weir BS. Truncated product method for combining p-values. Genet Epidemiol. 2002;22:170–185; Dudbridge F, Koeleman BPC. Rank truncated product of p-values, with application to genomewide association scans. Genet Epidemiol. 2003;25:360–366] or on Liptak combination allowed us, using Monte Carlo simulations, to demonstrate the possibility of mitigating the negative effect on power of combination-based multivariate permutation tests produced by an increasing level of correlation/association among responses.     

带工期指派的产品服务系统订单随机调度问题研究

针对由一个制造工厂和多个区域服务中心组成的服务型制造企业，研究了考虑生产时间和服务时间均具有随机性且工期可指派的产品服务系统（PSS）订单调度问题。首先以最小化订单提前、误工和工期指派费用的期望总额为目标构建问题的优化模型，然后分析目标函数近似值的最优性条件，据此提出加权最短平均生产时间排序规则，并结合该规则与插入邻域局部搜索设计了启发式算法对问题进行求解，最后通过数值仿真验证算法的可行性和有效性。研究表明，提前费用偏差对PSS订单调度与工期指派决策的影响很小，因此企业管理者无需准确估计库存费用也能制定出比较有效的PSS订单调度策略；而工期指派费用偏差对决策结果的影响非常大，因此企业管理者在决策时必须谨慎估计该项费用。     

Trying to stay ahead of the curve in Chile's economic development: exploring a way out of the middle‐income trap through pragmatic export development

Underneath impressive growth levels, the Chilean economy displays signs of being caught in a middle‐income trap. It has been unable to improve its productivity, increase the added value of its exports or upgrade its value chain. Its economy cannot compete either with low‐wage countries or highly productive, innovative countries. Its export strategy based on export promotion seems to have outlived its usefulness. It achieved remarkable quantitative success, but must now attend qualitative attributes. Instead of regarding market‐driven export promotion and state‐led export development as substitutes, this article proposes to view them as alternatives in different stages of development. To choose the appropriate time, more attention should be given to non‐traditional, structural indicators, like export sophistication and political‐institutional capabilities.     

区域多元化抑或产品多元化?制度环境约束下民营企业核心能力构建与成长战略选择

在文献与理论研究的基础上,构建了制度环境、核心能力与企业成长战略选择之间关系的概念模型,并提出了相关假设。然后,以中国民营上市公司2007-2014年数据为对象进行实证检验,结果发现:市场化程度更高的区域,民营企业倾向于构建"行业专家"型核心能力,进而倾向于选择"做强"的区域多元化战略;市场化程度相对较低的区域,民营企业更多倾向于构建"社会资本"型核心能力,进而会选择"做大"的产品多元化战略。上述发现为企业成长与多元化战略理论补充了新的内容。     

产品服务供应链的“双重收益共享”合作机制

产品与服务融合缓解了"供需错位"矛盾，使得产品服务供应链探索成为"供给侧结构性改革"下供需结构性匹配的重要路径。本文刻画产品服务视角下供应链组织结构的本质特征，构建产品服务供应链合作模型，探讨合作机制下"帕累托改进"区间存在性，揭示合作机制对产品服务供应链效率的作用机理。核心研究发现：供应链多元化组织结构加剧收益分配冲突，并导致服务规模与供应链效率"倒挂"现象，而合作机制下"双重收益共享"合作模型能提升产品服务供应链效率。     

基于职业性别隔离的女性就业创业问题研究--以成都市为例

女性就业是女性发展的基本内容，是女性获得经济独立并赢得社会性别平等的重要渠道。城镇居民就业普遍存在职业性别隔离且在水平与垂直方向均有所表现，女性职业（行业）普遍收入偏低，大量女性沉淀在职级较低岗位。文章以第六次人口普查数据为基础，统计了成都市30个服务行业与30个制造行业女性劳动力占所在行业的比例和女性就业结构构成，结合成都市人力资源市场岗位供给与求职需求分析，提出女性就业创业引导方向。     

基于在线评论数据的产品需求趋势挖掘

随着经济水平的提高和物质生活的丰富，消费者的需求变化也越来越快。能否迎合市场需求的变化是企业产品成功的关键。随着社交媒体的发展，消费者为了分享购物体验发表了许多在线评论信息，其中蕴含着消费者的需求变化。本文在产品特征提取和属性情感分析的基础上，构建了垃圾评论识别模型。然后，利用时间序列分析模型预测下阶段的产品属性关注度和情感计算。最后结合历史数据的变化趋势，分析产品属性的重要性和市场满意情况。利用汽车论坛上的汽车评论数据对本文提出的研究模型进行了验证。研究结果可以为企业制定营销策略以及产品改进与创新提供决策支持。     

技术创新与企业就业效应--基于微观企业调查数据的实证分析

利用2012年世界银行关于中国工业企业的调查数据，从流程创新、产品创新和企业研发三个维度分析了短期内技术创新对就业增长的影响。结果显示，流程创新与就业增长显著负相关；产品创新与就业增长显著负相关；企业研发与就业增长负相关，但较前两者显著性较弱。进一步研究发现，与东部沿海地区相比，中西部地区技术创新的就业替代效应更为明显。鉴于上述研究结果，对现有技术创新方式和政策提出相应的对策建议。     

Sum,product and ratio of Pareto and gamma variables

The exact distributions of X+Y, X Y and X/(X+Y) are studied when X and Y are independent Pareto and gamma random variables. Applications are discussed, to real problems in clinical trials, computer networks and economics.