The Non-Existence of the Labor Demand/Supply Diagram,and other Theorems of Institutional Economics

The most famous and influential diagram in modern (neoclassical) labor economics is the model of wage determination by supply and demand. Using concepts and ideas from institutional economics, I argue that the theory of a perfectly competitive labor market is logically contradictory and, hence, the demand/supply diagram cannot exist on the plane of pure theory. Four other fundamental theorems concerning labor markets are also derived, as are implications about the theoretical foundation of the field of industrial relations and the economic evaluation of labor and employment policy.

The Labor Market Participation of Sandwich Generation Italian Women

We empirically analyzed the labor market participation of Italian women, with special emphasis on the role of intergenerational family links. Older relatives, on the one hand, discourage the work participation of women by requiring care; on the other hand they may provide household services favoring labor supply. We studied this dual impact estimating a trivariate probit model where the three choices to be in the labor force, to use informal help from older relatives and to care for them are jointly determined. Our estimates show that care duties towards members of the previous generation hinder the labor market participation of Italian women, and that informal help received from older relatives strongly increases their probability of being engaged in paid work.

基于连续时间动态博弈的供应链声誉及其微分对策研究

着眼于企业及其供应链的可持续发展,纳入时间因素分析供应链协调问题.基于供应链视角考虑顾客价值开拓,并将其本质抽象为“供应链声誉”的构建过程.针对这一供应链动态协调问题,基于供应链成员企业之间的长期合作关系,在连续时间背景下采用变分法建立了供应链各方关于供应链声誉的微分对策模型,通过求解该模型发现在拟约束方程组有解时Nash均衡存在,并求出了相应的最优微分对策.这些理论研究结论阐明了长期的、稳定的合作关系对于实现供应链协调的意义,对于实践中供应链动态协调的实现具有一定的启发与参考价值.论文最后对相关结论进行了数值分析.     

Competitive and Collaborative Quality and Warranty Management in Supply Chains

Product quality and product warranty coverage are two important and closely related operational decisions. A longer warranty protection period can boost sales, but it may also result in dramatically increased warranty cost, if product quality is poor. To investigate how these two decisions interact with each other and influence supply chain performance, we develop a single‐period model with a supplier that provides a product to an original equipment manufacturer, which in turn sells it to customers. Customer demand is random and affected by the length of the product warranty period. Warranty costs are incurred by both the supplier and the manufacturer. We analyze two different scenarios based on which party sets the warranty period: manufacturer warranty and supplier warranty. Product quality is controlled by the supplier, and the manufacturer determines the ordering quantity. We analyze these decentralized systems and provide the structural properties of the equilibrium strategies. We also compare the results of centralized and decentralized systems and identify the conditions under which one system provides a longer warranty and better product quality than the other. Our numerical study further shows that, in decentralized settings, when the warranty period is determined by the firm sharing the larger proportion of total warranty costs, the supply chain can achieve greater system‐wide profit. Both parties can therefore benefit from properly delegating the warranty decision and sharing the resulting additional profit. We further design a supplier‐development and buy‐back contract for coordinating decentralized supply chains. Several extensions are also discussed.     

Value of and Interaction between Production Postponement and Information Sharing Strategies for Supply Chain Firms

We analyze the value of and interaction between production postponement and information sharing, which are two distinct strategies to reduce manufacturers’ uncertainty about demand. In both single‐level and two‐level supply chains, from the manufacturer's perspective, while information sharing is always valuable, production postponement can sometimes be detrimental. Furthermore, the value of production postponement is not merely driven by savings in inventory holding cost as postponement enables the manufacturer to avoid both excess and shortfall in production. We find that production postponement and information sharing strategies may substitute, complement, or conflict with each other, depending on the extent of the increase in the unit production cost when production is postponed. In a two‐level supply chain, from the retailer's perspective, information sharing and production postponement can be beneficial or detrimental. When information sharing is beneficial to the retailer, the retailer always shares her demand information with the manufacturer voluntarily. In addition, this voluntary information sharing is truthful because inflated or deflated demand information hurts the retailer through a higher wholesale price or a stock‐out. However, the retailer never shares her demand information voluntarily if the manufacturer has already adopted production postponement because production postponement and information sharing strategies always conflict with each other. Even when the retailer does not benefit from information sharing, we show that the manufacturer can always design an incentive mechanism to induce the retailer to share the demand information, irrespective of whether the manufacturer has already implemented production postponement or not. The above findings underscore the need for a careful assessment of demand uncertainty‐reduction strategies before the supply chain players embark upon them.     

Impacts of off‐farm employment on welfare,food security and poverty: Evidence from rural Vietnam

How off‐farm employment can enhance welfare in terms of food consumption and poverty alleviation is a critical question facing many developing countries. This study addressed that question by pursuing two objectives: (i) to quantify the impact of off‐farm employment on rural households’ welfare, food security and poverty; and (ii) to examine the factors that affect their decision to work off‐farm. Using panel data, we estimated a difference‐in‐difference combined with a propensity score matching model. The findings show that off‐farm employment improves income, ensures food security and contributes to poverty alleviation. The results also show that age, marital status, education, labour, financial capital, land, location, market access and losses from natural disasters are significant contributing factors to the decision to participate in off‐farm employment. The findings suggest that to improve the welfare of rural households, the Vietnamese government should proceed with policies that enhance their opportunities for participation in off‐farm employment.     

基于资金流服务商的供应链资金运作能力研究

高效的资金运作能力是决定一个企业乃至一条供应链成功的关键因素。本文提出了资金流服务商这一概念并重点分析了它所具备的两种资金运作能力:资金回收期压缩能力和采购资金占用压缩能力。在一个单周期的报童模型中,研究了资金流服务商通过给制造商提供这两种资金流服务能够给供应链整体收益带来的增大以及在这个过程中二者的利益分配问题。通过进一步比较这两种资金运作能力,验证了各自对于供应链的重要程度。     

基于PDCA的供应链视角下物流客户服务绩效评价研究

在系统总结国内外相关文献的基础上,设计了基于PDCA循环的供应链视角下物流客户服务绩效评价流程,并针对每个流程给出了控制重点,旨在通过对绩效评价流程的规范管理,不断提高物流客户服务绩效和供应链整体绩效水平。在绩效评价方案设计环节提出了给予供应链整体绩效提升的物流客户服务绩效评价方法和指标体系,在绩效评价方案实施环节给出了应用模糊层次分析法选择物流服务商的步骤。     

Designing Efficient Infrastructural Investment and Asset Transfer Mechanisms in Humanitarian Supply Chains

We analyze the efficacy of different asset transfer mechanisms and provide policy recommendations for the design of humanitarian supply chains. As a part of their preparedness effort, humanitarian organizations often make decisions on resource investments ex ante because doing so allows for rapid response if an adverse event occurs. However, programs typically operate under funding constraints and donor earmarks with autonomous decision‐making authority resting with the local entities, which makes the design of efficient humanitarian supply chains a challenging problem. We formulate this problem in an agency setting with two independent aid programs, where different asset transfer mechanisms are considered and where investments in resources are of two types: primary resources that are needed for providing the aid and infrastructural investments that improve the operation of the aid program in using the primary resources. The primary resources are acquired from earmarked donations. We show that allowing aid programs the flexibility of transferring primary resources improves the efficiency of the system by yielding greater social welfare than when this flexibility does not exist. More importantly, we show that a central entity that can acquire primary resources from one program and sell them to the other program can further improve system efficiency by providing a mechanism that facilitates the transfer of primary resources and eliminates losses from gaming. This outcome is achieved without depriving the individual aid programs of their decision‐making autonomy while maintaining the constraints under which they operate. We find that outcomes with centralized resource transfer but decentralized infrastructural investments by the aid programs are the same as with a completely centralized system (where both resource transfer and infrastructural investments are centralized).     

Buttressing Supply Chains against Floods in Asia for Humanitarian Relief and Economic Recovery

Floods are the most frequent category of disasters worldwide. Among all geographic regions, Asia has suffered the most. While there are several ongoing humanitarian efforts and initiatives, we believe there is a new opportunity to coordinate “last mile” humanitarian efforts in the event of a flood using micro‐retailers. Because micro‐retailers are the “last mile” nodes in traditional retail supply chains in many Asian countries, we propose the use of social enterprise to buttress these supply chains for distribution of essential goods by coordinating with micro‐retailers before and after floods. We also present a stylized model to quantify the benefits of doing so.