Binary Response Models for Panel Data: Identification and Information

This paper considers a panel data model for predicting a binary outcome. The conditional probability of a positive response is obtained by evaluating a given distribution function (F) at a linear combination of the predictor variables. One of the predictor variables is unobserved. It is a random effect that varies across individuals but is constant over time. The semiparametric aspect is that the conditional distribution of the random effect, given the predictor variables, is unrestricted. This paper has two results. If the support of the observed predictor variables is bounded, then identification is possible only in the logistic case. Even if the support is unbounded, so that (from Manski (1987)) identification holds quite generally, the information bound is zero unless F is logistic. Hence consistent estimation at the standard pn rate is possible only in the logistic case.     

Auftragsklärung: Interventionen auf dem Wege zur Konstituierung eines Beratungssystems*

The author demonstrates basing on a case study, that the development of a consultation system is a process that requires time and patience of everyone involved. Not a fast decided definition of a consultation method with the corresponding setting is the first step but a clarification of the request. That is what the author is pleading for a phase of detailed analysis with the potential client.     

International accounting: a French perspective

The objective of this article is to show how slow and imperfect the international accounting harmonization and standardization process is, based on the example of France but also some other European countries. One of the explanations is that accounting is a mirror of a society. Therefore, international harmonization and standardization is a response to social needs, a compromise among different interests, not only a technical process.     

Robust trading mechanisms over 0/1 polytopes

The problem of designing a trade mechanism (for an indivisible good) between a seller and a buyer is studied in the setting of discrete valuations of both parties using tools of finite-dimensional optimization. A robust trade design is defined as one which allows both traders a dominant strategy implementation independent of other traders’ valuations with participation incentive and no intermediary (i.e., under budget balance). The design problem which is initially formulated as a mixed-integer non-linear non-convex feasibility problem is transformed into a linear integer feasibility problem by duality arguments, and its explicit solution corresponding to posted price optimal mechanisms is derived along with full characterization of the convex hull of integer solutions. A further robustness concept is then introduced for a central planner unsure about the buyer or seller valuation distribution, a corresponding worst-case design problem over a set of possible distributions is formulated as an integer linear programming problem, and a polynomial solution procedure is given. When budget balance requirement is relaxed to feasibility only, i.e., when one allows an intermediary maximizing the expected surplus from trade, a characterization of the optimal robust trade as the solution of a simple linear program is given. A modified VCG mechanism turns out to be optimal.     

用线性互补及二次规划理论分析市场均衡问题

本文讨论了一类完全竞争条件下的市场均衡问题,供给方的生产特征用线性规划模型进行刻划,市场需求函数源于一般经济意义下的模型,它是一系列相互独立的价格变量的函数．我们将此问题归结为线性互补问题,并依此讨论了均衡点的存在性．本文还讨论了一种用二次规划进行刻划的经济问题,并指出此二次规划的K－K－T条件等价于所讨论的线性互补问题．     

Cost-Benefit Analysis of All-Terrain Vehicles at the CPSC1

The present value of the costs of injuries and deaths associated with each unit of a product is a useful number in conducting cost-benefit analysis at the CPSC. Before a remedy is known, this value indicates the approximate amount that it is worth spending on a fix; similarly, if a fix is proposed, this number indicates whether it is cost-justified. The method of analysis is applied to all-terrain vehicles. Injury costs per vehicle are estimated. Determinants of accidents are estimated using a logit regression model applied to surveys of users and of accident victims; this indicates factors associated with accidents, and is used to estimate marginal probabilities. Costs of various vehicle components are estimated using a hedonic price index. This information (injury costs, accident probabilities, and component cost) is combined in a benefit–cost analysis of proposed remedies.     

Any Maximal Planar Graph with Only One Separating Triangle is Hamiltonian

A graph is hamiltonian if it has a hamiltonian cycle. It is well-known that Tutte proved that any 4-connected planar graph is hamiltonian. It is also well-known that the problem of determining whether a 3-connected planar graph is hamiltonian is NP-complete. In particular, Chvátal and Wigderson had independently shown that the problem of determining whether a maximal planar graph is hamiltonian is NP-complete. A classical theorem of Whitney says that any maximal planar graph with no separating triangles is hamiltonian, where a separating triangle is a triangle whose removal separates the graph. Note that if a planar graph has separating triangles, then it can not be 4-connected and therefore Tutte's result can not be applied. In this paper, we shall prove that any maximal planar graph with only one separating triangle is still hamiltonian.     

Production and changeover control policies of a class of failure prone buffered flow-shops

This article deals with a stochastic optimal control problem for a class of buffered multi-parts flow-shops manufacturing system. The involved machines are subject to random breakdowns and repairs. The flow-shop under consideration is not completely flexible and hence requires setup time and cost in order to switch the production from a part type to another, this changeover is carried on the whole line. Our objective is to find the production plan and the sequence of setups that minimise the cost function, which penalises inventories/backlogs and setups. A continuous dynamic programming formulation of the problem is presented. Then, a numerical scheme is adopted to solve the obtained optimality conditions equations for a two buffered serial machines two parts case. A complete heuristic policy, based on the numerical observations which describe the optimal policies in system states, is developed. It will be shown that the obtained policy is a combination of a KANBAN/CONWIP and a modified hedging corridor policy. Moreover, based on our observations and existent research studies extension to cover more complex flow-shops is henceforth possible. The robustness of such a policy is illustrated through sensitivity analysis.     

Virtuelles Selbstcoaching — Konzept und erste Erfahrungen

Combining management consultation with psychotherapy in the early nineties, coaching is a real innovation. Its success story grounds on a huge market demand. Nevertheless, actual market observations revealed a declining success progress over the past years caused by two factors. The first one refers to economic reasons since coaching is a high-budget-product and focuses mainly on managers and important specialists. The second factor is a psychological one: many potential clients associate coaching with psychotherapy and therefore react with resistance. To continue the progress, it is necessary to overcome both restrictions. The solution is virtual self-coaching as an innovative combination of coaching and e-learning. It is an online-tool that guides the user through a well-defined path of problem solving questions. This is for many users attractive because of the low costs in combination with the fact that working with an online-tool is associated with further education and not therapy. Our tests have demonstrated that the program is useful for a big variety of different problems and that best results can be expected if virtual self-coaching is combined with telephone coaching.     

Classifying capital projects for top management decision-making

This paper is an attempt to redress a perceived imbalance in the research and literature of capital project analysis. There is a plethora of work on the quantitative aspects of project analysis, yet empirical surveys show limited use of such techniques. There is limited work on the organizational processes of project selection, but there appears to be little or no work taking place on formal organizational systems for project selection.The more quantitative literature generally takes a deductive approach using a model developed from microeconomics based on the assumption that the objective of the firm is the maximization of owners' wealth. In this paper it is argued that there is a need to take an inductive approach and place the capital investment decision in its organizational setting. This paper looks at the formal capital budgeting system within the corporate setting.It is suggested that the specific capital investment decision takes place against the background of a set of policies and constraints, which are more or less explicit.The selection of corporate projects is a complex issue, but to provide some structure so that the problems can be processed by the organization, a capital budgeting system is designed. Part of this system is the classification of projects according to some criteria. It would therefore appear that the purpose of this classification system is to aid capital project selection within an organizational context.A consideration of classification systems for capital projects is undertaken, this is followed by a survey of the classification systems which have been proposed in the capital investment literature. Finally a classification system based upon specific criteria is proposed.     

Functional Approximation and Optimal Specification of the Mechanical Risk Index

The mechanical risk index (MRI) is a numerical measure that quantifies the complexity of drilling a well. The purpose of this article is to examine the role of the component factors of the MRI and its structural and parametric assumptions. A meta-modeling methodology is applied to derive functional expressions of the MRI, and it is shown that the MRI can be approximated in terms of a linear functional. The variation between the MRI measure and its functional specification is determined empirically, and for a reasonable design space, the functional specification is shown to a good approximating representation. A drilling risk index is introduced to quantify the uncertainty in the time and cost associated with drilling a well. A general methodology is outlined to create an optimal MRI specification.     

A characterization of graphs with disjoint dominating and paired-dominating sets

A dominating set of a graph is a set of vertices such that every vertex not in the set is adjacent to a vertex in the set, while a paired-dominating set of a graph is a set of vertices such that every vertex is adjacent to a vertex in the set and the subgraph induced by the set contains a perfect matching. In this paper, we provide a constructive characterization of graphs whose vertex set can be partitioned into a dominating set and a paired-dominating set.     

Centralization versus decentralization: Risk pooling,risk diversification,and supply chain disruptions

We investigate optimal system design in a multi-location system in which supply is subject to disruptions. We examine the expected costs and cost variances of the system in both a centralized and a decentralized inventory system. We show that, when demand is deterministic and supply may be disrupted, using a decentralized inventory design reduces cost variance through the risk diversification effect, and therefore a decentralized inventory system is optimal. This is in contrast to the classical result that when supply is deterministic and demand is stochastic, centralization is optimal due to the risk-pooling effect. When both supply may be disrupted and demand is stochastic, we demonstrate that a risk-averse firm should typically choose a decentralized inventory system design.     

SENSITIVITY ANALYSIS WITH INTERACTION EFFECTS

The purpose of this paper is to extend the sensitivity analysis methodology as it applies to linear programming. The methodology developed herein is concerned with those changes in a technological coefficient that cause simultaneous changes in the relevant cost coefficients of the objective function. By proceeding from the definitions of feasibility and optimality, the authors develop formulas for determining bounds on the extent to which a technological coefficient, which has a predetermined effect on the corresponding cost coefficient, can vary without changing the optimal set of activities. After the formulas are developed, their use is demonstrated on a product-mix problem. This technique is of interest because changes in the rate at which an input is utilized can be expected to change the cost per unit of a resulting product. This interdependence should be recognized whenever a sensitivity analysis is performed on a technological coefficient of either a cost minimization or a contribution margin maximization problem.     

具有时变运输时间的JIT系统批量决策

本文的研究对象是由制造商、配送中心和零售商组成的多级供应链系统,其中零售商要求制造商为其提供短时间间隔、小批量的JIT配送。研究内容为在时变运输时间影响下的供应链系统批量决策问题。在实际运输时间数据的基础上建立了时变运输时间的函数,并以此构建了系统的总成本函数,并在相关文献研究的基础上采用新的更为有效搜索规则进行了求解。根据求解规则,采用ActiveX自动化技术将Matlab的数值计算功能嵌入Visual Basic的集成开发环境中,开发了对应的决策支持系统。最后进行了敏感性分析并提供了低运作成本的决策支持方案。     

A Reality Check for Data Snooping

Data snooping occurs when a given set of data is used more than once for purposes of inference or model selection. When such data reuse occurs, there is always the possibility that any satisfactory results obtained may simply be due to chance rather than to any merit inherent in the method yielding the results. This problem is practically unavoidable in the analysis of time‐series data, as typically only a single history measuring a given phenomenon of interest is available for analysis. It is widely acknowledged by empirical researchers that data snooping is a dangerous practice to be avoided, but in fact it is endemic. The main problem has been a lack of sufficiently simple practical methods capable of assessing the potential dangers of data snooping in a given situation. Our purpose here is to provide such methods by specifying a straightforward procedure for testing the null hypothesis that the best model encountered in a specification search has no predictive superiority over a given benchmark model. This permits data snooping to be undertaken with some degree of confidence that one will not mistake results that could have been generated by chance for genuinely good results.     

Optimal testing and repairing a failed series system

We consider a series repairable system that includes n components and assume that it has just failed because exactly one of its components has failed. The failed component is unknown. Probability of each component to be responsible for the failure is given. Each component can be tested and repaired at given costs. Both testing and repairing operations are assumed to be perfect, that is, the result of testing a component is a true information that this component is failed or active (not failed), and the result of repairing is that the component becomes active. The problem is to find a sequence of testing and repairing operations over the components such that the system is always repaired and the total expected cost of testing and repairing the components is minimized. We show that this problem is equivalent to minimizing a quadratic pseudo-boolean function. Polynomially solvable special cases of the latter problem are identified and a fully polynomial time approximation scheme (FPTAS) is derived for the general case. Computer experiments are provided to demonstrate high efficiency of the proposed FPTAS. In particular, it is able to find a solution with relative error ɛ = 0.1 for problems with more than 4000 components within 5 minutes on a standard PC with 1.2 Mhz processor.     

终极所有权、层级结构与信息泄露——来自控制权转让市场的经验证据

本文探讨了控制权转让市场中收购方终极所有权、层级与信息泄露之间的关系。研究发现收购方的终极所有权属性与信息泄露严重程度有着显著的相关关系。当收购人为民营企业时,非公开收购信息进入股价的速度要明显的慢于国有企业收购人;当地方国有企业为收购人时,其非公开收购信息进入股价的速度又明显的快于其他两类企业。表明民营企业维护收购信息的机密性的动机最强,而地方国有企业收购信息则最容易被市场察觉。与预期不一致的是,公司的层级结构与信息泄露速度没有显著的关系,这一发现意味着收购等重大事件的决策权集中在控制链最上层控制人手中,下层企业只是执行这些决策的工具。     

基于研究领域匹配度的科研项目评审指派方法

针对科研项目评审中的项目指派问题,提出了一种基于研究领域匹配度的指派方法。首先给出了项目与评审专家研究领域匹配度的度量模型。在此基础上,考虑项目与评审专家研究领域的匹配情况,构建了将项目指派给不同评审专家的决策模型,并给出了模型的求解方法,最后通过算例说明了方法的可行性。     

需求预测更新情形下的供应链Stackelberg博弈与协调研究

在贝叶斯需求预测更新的情形下,从供需博弈角度探讨了易逝品供应链库存管理的基本问题:什么时间订、订多少以及订货价格如何决定。建立了制造商为主方、零售商为从方的供需Stackelberg博弈模型,其中制造商在低价多量与高价少量之间权衡,零售商在低成本低预测精度与高成本高预测精度之间进行权衡。分析了模型最优解的存在性,设计了两层规划的分段迭代算法,并通过数值例子说明了模型与算法的有效性。进一步,针对Stackelberg博弈中出现的双重边际效应,提出了实现供应链协调的契约形式,论证了实现供应链协调的条件。