中国农村人口迁移模型探索——一个对"民工荒"现象新的解释

本文构造了一个理论模型,得出了人口流动均衡条件,从而对“民工荒”现象做出了新的解释。本文的结论是迁移成本和就业概率决定了迁移人口的规模;农村工业部门的发展不仅分担城市就业压力,还缩小农民流动规模;农产品价格波动表示的农业剩余波动使得劳动力无限供给神话提前破灭,但并不意味着二元经济的终结。     

异质性企业、结构转型与稳定出口

通过构建异质性企业、结构转型和出口增长的二元边际理论模型,本文认为转型国家出口增长主要沿集约边际实现的原因与其农业剩余劳动力有关,农业剩余劳动力越多,出口增长的集约边际越大、扩展边际越小。利用Tobit模型对1995-2009年中国出口到123个国家的HS-6位码贸易数据进行实证分析,在控制其他影响因素的前提下,我国农业剩余劳动力非农转移显著正向影响出口增长集约边际、负向影响扩展边际的效应确实存在。经济规模、贸易成本、人民币升值、区域经济一体化、外部冲击、语言的相通性、政治体制等变量对中国出口增长二元边际的影响机制不完全相同,表明要提高出口增长中的扩展边际比重,出口企业应实施市场多元化战略,将目标市场从传统高收入国家转移到发展中国家来,实现出口的稳定增长。     

Economies of traffic density and scale in the integrated air cargo industry: The cost structures of FedEx Express and UPS Airlines

This paper examines the cost structures of the leading integrated air cargo carriers, FedEx Express and UPS Airlines. A total cost model is estimated for the two carriers using quarterly data on domestic operations and costs over a nine-year period (2003–2011). The estimated model indicates that the integrated industry exhibits increasing returns to traffic density and constant returns to scale. Accounting for carrier-specific differences in cost structure and network size, FedEx Express is found to be more cost-efficient than UPS Airlines. Looking at the carriers individually, UPS Airlines exhibits substantial economies of traffic density and constant returns to scale while FedEx Express' cost structure is characterized by weak economies of density and constant returns to scale. The combined effect of returns to density and returns to scale on the cost structures of integrated carriers is captured by economies of size. Both FedEx Express and UPS Airlines exhibit economies of size, indicating that carriers in the integrated industry can be more cost efficient by making appropriate adjustments to their network size as their output grows. Moreover, the relative cost-efficiencies of the carriers are reversed when their network-size differences are not controlled.     

论双电源切换装置的特点

双电源切换装置是一级负荷和其他重要负荷等用电设备中经常使用的关键设备。随着科技发展,双电源切换装置已有多种产品和型式供用户选择。本文重点对“Y”型和“H”型双电源切换装置的原理、发展过程、特点等进行论述,为电气设计、采购、及维护人员提供技术参考。     

双层网络嵌入下结构洞对企业二元创新的影响研究

网络结构特征影响企业知识转移与知识组合效果,进而对创新绩效产生复杂作用。利用我国165家上市企业2007—2018年专利面板数据,实证检验企业知识与协同双层网络嵌入对二元创新绩效的影响,并分析战略柔性和开放度对上述关系的调节作用。研究结果表明,企业知识网络结构洞正向影响利用式创新绩效,负向影响探索式创新绩效;协同网络结构洞与二元创新均存在负相关关系。同时,战略柔性和开放度调节双层网络结构洞与二元创新的关系,且变量间存在有效匹配关系：知识网络结构洞—开放度促进利用式创新绩效提升,而协同网络结构洞—战略柔性促进探索式创新绩效提升。研究结论为解决结构洞与企业创新关系的分歧带来新思路,同时为企业创新绩效提升提供理论借鉴。     

三重二元结构下的人口流动模型：对民工荒的一个新的研究框架

传统的人口流动模型建立在单一的城乡二元经济基础之上,不完全适合解释中国的人口流动问题,尤其不能解释民工荒现象。本文依据中国特殊的城乡和区域双重二元经济以及城乡二元社会结构下人口流动的特殊性,对传统人口流动模型进行修正,建立了新的人口流动模型,并以此分析我国产生民工荒现象的原因,提出解决民工荒问题的政策建议。     

中国的劳动收入份额为什么趋于下降?——基于二元经济模型的观察与解释

新古典经济学的要素分配理论以劳动力是稀缺资源作为其前提假设,与我国二元经济条件下的现实情况存在较大差距,因而在分析我国劳动收入份额下降时解释力不足。文章修正了新古典经济学的劳动力稀缺要素假定,基于劳动力无限供给假定的二元经济模型和中国数据表现出的异质性特征,建立了一个分析二元经济中劳动收入份额影响因素的理论框架,并运用该理论框架解释了中国劳动收入份额趋降的原因,提出促进劳动密集型技术进步、提高人力资本禀赋、审慎干预劳动市场等方面的政策建议。     

Dual market competition and deposit rate setting in Islamic and conventional banks

This paper addresses the issue of competition in dual banking markets by analyzing the determinants of deposit rates in Islamic and conventional banks. Using a sample of 20 countries with dual banking systems over the 2000–2014 period, our results show significant differences in the drivers of Islamic and conventional banks' pricing behavior. Conventional banks with stronger market power set lower deposit rates but market power is not significant for Islamic banks. In predominantly Muslim environments, conventional banks set higher deposit rates and further higher when their market power is lower. Whereas conventional banks are influenced by the competitiveness of Islamic banks, Islamic banks are only affected by their peers in predominantly Muslim countries. Our findings have important implications regarding competition and bank stability in dual banking markets.     

我国寿险公司范围经济效应的实证研究

我国自1996年实施产寿分业经营以来,人身保险业务快速增长,寿险公司数量急剧增加,寿险公司业务中新型寿险的比重不断上升,呈现出"一险独大"的市场状况。运用超越对数成本函数,对国内29家具有代表性的寿险公司2005-2010年期间的范围经济状况进行检验的结果显示:不同规模和背景的寿险公司的范围经济系数均比较明显,但是很多寿险公司所表现出来的范围经济性具有"欺骗性"。因此,寿险业务结构调整缺乏内部的市场激励,需要强有力的外部力量推动。     

A New Typology for Economic Sectors with a view to Policy Implications

This paper is an attempt to tease out a typology of economic sectors based on a systems approach to innovation and economic growth that may be useful for policy analysis. The typology explored here revolves around novel products rather than ethereal knowledge-producing entities. This insight goes back to Allyn Young (1928) and Joseph Schumpeter (1934) who argued that the introduction of new goods was the engine of economic growth. More precisely, our typology of sectors focuses on novel products which are efficiency-enhancing within and between sectors through the market mechanism. The scheme revolves around the relationship between 'Enabling' and 'Recipient' sectors (which gives the typology its name: ER), and offers a lens for viewing and interpreting a substantive part of the mechanics of modern economic growth. The last part of the paper briefly discusses a few immediate policy implications, although it has the potential for greater use and value in this regard.