Strategic design and operational management optimization of a multi stage physical distribution system

Design and management of logistic networks is one of the most critical issues in supply chain management. However, the literature does not contain any effective models, methods, and applications that simultaneously support management decisions in the strategic design of the distribution system, in the operational planning and organization of vehicles, and in container trips organization adopting different modes of transportation. The aim of this paper is to illustrate an original framework for the design and optimization of a multi echelon and multi level production/distribution system that combines mixed-integer linear programming modeling with cluster analysis, heuristic algorithms, and optimal transportation rules. A significant case study is illustrated revealing the effectiveness of the approach and tools proposed.     

A nonparametric test for equality of distributions with mixed categorical and continuous data

In this paper we consider the problem of testing for equality of two density or two conditional density functions defined over mixed discrete and continuous variables. We smooth both the discrete and continuous variables, with the smoothing parameters chosen via least-squares cross-validation. The test statistics are shown to have (asymptotic) normal null distributions. However, we advocate the use of bootstrap methods in order to better approximate their null distribution in finite-sample settings and we provide asymptotic validity of the proposed bootstrap method. Simulations show that the proposed tests have better power than both conventional frequency-based tests and smoothing tests based on ad hoc smoothing parameter selection, while a demonstrative empirical application to the joint distribution of earnings and educational attainment underscores the utility of the proposed approach in mixed data settings.     

双边受控溢出下企业合作研发的博弈分析

技术溢出的高低受到企业间创新技术接近程度的影响,技术溢出并非仅仅是从事创新的企业单方选择的结果,而是企业双方技术路径选择组合的结果。基于“企业间的技术越兼容,技术溢出越高”的假设,将创新技术决策引入传统的双寡头博弈模型,对比分析企业创新技术选择的动机及其影响。研究结果表明：无论是合作模式还是非合作模式下,追求利润最大化的企业总会选择相同或相似的创新技术;而社会最优技术差距高于利润最大化的技术差距。因此,在技术溢出较高的行业,非合作模式可能会导致较低的社会福利,政府应当鼓励企业形成创新联盟或专利联营。     

成本收益差异的房地产不对称双头期权博弈模型分析

文章运用不对称双寡头期权博弈模型考察在房地产开发项目中企业的策略投资决策。模型中,房地产开发企业的项目投资有固定的建设周期,项目产生现金流是在建成以后;并且,投资具有投资成本先动优势和投资收益后动优势,即追随企业的投资成本和租金流均高于领先企业。分析表明,建设周期、投资成本、投资成本先动优势、垄断投资收益、后动投资收益、商品房市场需求波动度等因素都影响企业的投资决策。存在投资成本差异的阈值,将两企业均衡投资策略划分为先占均衡、序列均衡和等待均衡。     

MICROFINANCE PENETRATION AND ITS INFLUENCE ON CREDIT CHOICE IN INDONESIA: EVIDENCE FROM A HOUSEHOLD PANEL SURVEY

This paper studies empirical determinants of how heterogeneous households are matched to different types of loan products in a credit market in Indonesia. A unique situation arose when a microfinance institution launched operations in our survey area during the survey period, and we utilized its market entry for conducting mixed logit analysis of households’ credit choices. Time-varying choice sets help us identify parameters regarding preferences for various credit attributes. Our results show that the new availability of small-scale loans without collateral requirement greatly increases households’ probability of obtaining credit overall. Households in self-employed business prefer formal credit as a stable financing source but are impeded in receiving it when they locate in a rural area, probably because of large transaction costs. The poorest households, however, might not be able to exploit new credit opportunities as much as richer households, even if the scale of credit is very small.     

Personalized pricing and advertising: An asymmetric equilibrium analysis

We study personalized price competition with costly advertising among n quality-cost differentiated firms. Strategies involve mixing over both prices and whether to advertise. In equilibrium, only the top two firms advertise, earning “Bertrand-like” profits. Welfare losses initially rise then fall with the ad cost, with losses due to excessive advertising and sales by the “wrong” firm. When firms are symmetric, the symmetric equilibrium yields perverse comparative statics and is unstable. Our key results apply when demand is elastic, when ad costs are heterogeneous, and with noise in consumer tastes.     

Can privatization be a catalyst for environmental R&D and result in a cleaner environment?

In this paper we explore whether privatization helps to catalyze a firm's environmental research and development (ER&D) and improve environmental quality. By defining ER&D as the effort undertaken by a firm to reduce its pollution per unit of output, we find in a duopoly framework that privatization cannot catalyze both public and private firms’ ER&D efforts simultaneously; it can increase one but decrease the other firm's investment, or it may even lower both firms’ ER&D investments. Moreover, when production causes severe environmental damage, or the imposition of environmental taxes poorly internalize the pollution externality, privatization may result in a poorer environment. For the sake of having a cleaner environment, policy-makers can impose higher environmental taxes on a highly polluting industry when it is being privatized.     

Robust hub network design problem

This paper presents a robust formulation for the uncapacitated single and multiple allocation hub location problem where demand is uncertain and its distribution is not fully specified. The proposed robust model is formulated as a mixed integer nonlinear program and then transformed into a mixed integer conic quadratic program. An efficient linear relaxation strategy is proposed which is found to deliver the optimal solutions for all the cases considered in this paper. Numerical experiments suggest location of more number of hubs when accounting for demand uncertainty using robust optimization compared to the deterministic setting.     

Smartphone preferences and brand loyalty: A discrete choice model reflecting the reference point and peer effect

Brand loyalty and interest have significant impacts on consumers' smartphone choices. What about brand loyalty and interest of smartphone in South Korea where Samsung originates from? This study investigates brand loyalty and interest and how they are affected by the satisfaction of innovative peers in South Korea. An asymmetric discrete choice model with reference-dependent preferences is applied for the analysis. The estimation results show that in South Korea the brand is the most important attribute of smartphone and Apple is the strongest in brand loyalty. Whether consumers who are currently owners of Apple smartphones continue to maintain the same brand in their next purchasing depends not only on their brand loyalty but also on the satisfaction of their highly innovative peers who currently own the Apple. On the other hand, Samsung's brand loyalty is lower than that of Apple, but the brand interest is the highest. Additionally, in all smartphone brands, satisfaction with smartphone brands owned by innovative peers has a significant impact on consumers' interest.     

Aircraft line maintenance scheduling and optimisation

With the advent of new technologies and more modern aircraft, many of the maintenance jobs traditionally scheduled for periodic block checks can now be performed in the ‘‘line maintenance” environment, i.e., during layovers between scheduled flights of an aircraft. This flexibility can be exploited to reduce maintenance costs and improve fleet utilisation of an airline. In this paper we introduce and study the Line Maintenance Scheduling Problem (LMSP). The LMSP assigns jobs to available maintenance opportunities, defined by aircraft routes, and sets the starting time for each job. Its objective is to minimise the deviation from this schedule with respect to given due dates for each task, without exceeding resource capacity at the airports at any moment. We formulate the LMSP as a mixed integer programming problem, and describe and compare two solution approaches for this problem: an integrated exact solution algorithm, which solves job assignment and timetabling simultaneously, and a sequential, heuristic approach. We tested our algorithms on a set of instances inspired on data provided by an industry partner. Our experiments show the applicability of both approaches on realistic settings: the exact approach was able to find the optimal solution for all instances, in less than 10 min on average. Our analysis also shows with an example that line maintenance can be more efficient when capacity is spatially spread, even if the total capacity is reduced.