The Potential for Endogeneity Bias in Data Envelopment Analysis

Data envelopment analysis has become an important technique for modelling the relationship between inputs and outputs in the production process, particularly in the public sector. However, whenever measures of the output of public sector activity receive public attention, there is a strong possibility that there will be a feedback from the achieved output to the resources devoted to the activity. In other words, the level of resources is endogenous. The implications of such endogeneity for standard econometric estimation techniques are well known, and methods exist to deal with the problem. Most commentators have assumed that endogeneity poses no analogous problems for DEA because the technique merely places an envelope around feasible production possibilities. Using Monte Carlo simulation techniques, however, this paper shows that the efficiency estimates generated by DEA in the presence of endogeneity can be subject to bias, in the sense that inefficient units using low levels of the endogenous resource may be set tougher efficiency targets than equally inefficient units using more of the resource, particularly when sample sizes are small. The paper concludes that, in such circumstances, great caution should be exercised when comparing efficiency measures for units using different levels of the endogenous input.     

The effect of variety seeking behaviour on optimal product positioning

In this paper we develop a stochastic (first order Markovian) consumer choice model that represents variety seeking behaviour and we investigate the practical implications of this model for optimal product positioning relative to a zero order model that does not incorporate variety seeking. We show that the optimal positioning implications of a variety seeking process is indeed different than those of a (no-variety-seeking) zero order process. Based on intuition, one might expect increased variety seeking to imply that firms should increase the distance between their products in an attribute space. In fact, we show that this effect does occur for relatively low share brands. But just the opposite effect holds for relatively high share brands. That is, variety seeking behaviour generates a desire to more differentiation among low share brands, and a desire for less differentiation among high share brands.     

Introducing competition in healthcare services: The role of private care and increased patient mobility

We study the operational implications from competition in the provision of healthcare services, in the context of national public healthcare systems in Europe. Specifically, we study the potential impact of two alternative ways through which policy makers have introduced such competition: (i) via the introduction of private hospitals to operate alongside public hospitals and (ii) via the introduction of increased patient choice to grant European patients the freedom to choose the country they receive treatment at. We use a game-theoretic framework with a queueing component to capture the interactions among the patients, the hospitals and the healthcare funders. Specifically, we analyze two different sequential games and obtain closed form expressions for the patients’ waiting time and the funders’ reimbursement cost in equilibrium. We show that the presence of a private provider can be beneficial to the public system: the patients’ waiting time will decrease and the funders’ cost can decrease under certain conditions. Also, we show that the cross-border healthcare policy, which increases patient mobility, can also be beneficial to the public systems: when welfare requirements across countries are sufficiently close, all funders can reduce their costs without increasing the patients’ waiting time. Our analysis implies that in border regions, where the cost of crossing the border is low, “outsourcing” the high-cost country’s elective care services to the low-cost country is a viable strategy from which both countries’ systems can benefit.     

考虑相互信息监督下的服务合作生产契约

知识密集型服务合作生产由于存在相互之间的知识依赖和信息粘性,双方信息管理效率影响合作激励机制的设计。从相互信息监督视角出发,综合考虑双方信息监督效率和相对重要性参数对服务合作生产契约设计的影响。结果表明,在双方信息监督效率相同情况下,相对更重要的一方拥有剩余激励是最优的;在双方信息监督效率不同时,让监督更有效且相对更重要的一方拥有剩余激励是最优的;如果监督效率优势和相对重要性优势没有集中于一方,则结果取决于两者的比较,具有更强优势的一方应该成为剩余激励索取者。双方的相对重要性和信息监督效率共同决定合作契约。     

湖南省公共医疗卫生支出效率及其影响因素实证分析

利用DEA-Tobit两阶段分析法,计算出2009-2013年5年间湖南省14个地级市政府公共医疗卫生支出的综合技术效率值、纯技术效率值、规模效率值三种效率值,分析出湖南省各地级市政府公共医疗卫生支出所处规模报酬阶段,并对反映卫生支出资金配置的综合技术效率水平的外部影响因素加以回归分析.结果发现:湖南省各地区公共医疗卫生效率水平整体水平偏低并且存在明显的差异性,除长沙以外的其他地级市政府公共医疗卫生支出均处于不同程度的非充分效率水平.湖南省各地区人均生产总值及城市化水平对公共医疗卫生支出效率有显著的促进作用.教育水平、人口密度、居民人均可支配收入对湖南省公共医疗卫生支出效率的提高有阻碍作用.     

Limited resoluteness and strategic voting: The case of linear sincere preference orderings

This note is concerned with the strategic manipulation of the aggregation procedures, which for every profile of individual preference orderings and every set of alternatives (presented for choice) specify a non-empty subset of alternatives. In the context of multi–valued aggregation procedures, the strategic behaviour of an individual crucially depends on the criterion of comparing different subsets of alternatives. It is shown that when the sincere (or true) preference orderings are restricted to be strict, the requirement of resoluteness in pairwise choice is the frontier between the manipulability and non-manipulability results in social choice as long as individuals adopt some versions of the sure-thing principle in comparing different subsets of alternatives.     

四方主体参与下的环境规制演化博弈分析

环境污染问题严重阻碍了我国经济和社会的发展,我国当下的环境治理逐步形成多主体治理模式。本文将环境治理中的四个主要相关主体“中央政府-地方政府-企业-公众”置于统一框架下,建立了四方演化博弈模型,并利用数值仿真模拟参数变化对博弈系统不同主体稳定策略的影响,得到以下结论:(1)四方演化博弈系统的16个纯策略均衡点中,共有8个条件稳定点,其余8个均衡点在任何条件下都不稳定。其中8个条件稳定点代表着我国环境治理中各利益相关主体可能呈现的策略均衡,策略集中某策略的相对净收益决定了相关主体的策略选择。(2)通过数值仿真分析发现,增大中央政府对地方政府消极执行的处罚、增大中央政府转移支付和增大中央政府对地方政府消极执行的追加处罚不仅能够提升地方政府的环保执法力度,而且可以提高企业减排积极性。提高环境规制标准、增大对企业非法排污的处罚,对地方政府、企业和公众的策略选择都会产生影响,可以使系统更快向“中央政府不严格监管、地方政府积极执行、企业合法排污、公众不举报”的理想稳定状态演化,但提高环境规制标准的效果会略优于加大对企业处罚。地方政府增大企业治污补贴短期内可有利于实现经济的可持续发展,但过高的企业治污补贴将不利于博弈系统达到理想稳定状态,是一种非长效的环境治理模式。提高公众举报奖励可以促使企业合法排污,并在一定程度上加快实现博弈系统的理想稳定状态。最后,分别从中央政府、地方政府和公众角度提出了环境治理的相关建议。     

Bayesian Inference for Extremes: Accounting for the Three Extremal Types

The Extremal Types Theorem identifies three distinct types of extremal behaviour. Two different strategies for statistical inference for extreme values have been developed to exploit this asymptotic representation. One strategy uses a model for which the three types are combined into a unified parametric family with the shape parameter of the family determining the type: positive (Fréchet), zero (Gumbel), and negative (negative Weibull). This form of approach never selects the Gumbel type as that type is reduced to a single point in a continuous parameter space. The other strategy first selects the extremal type, based on hypothesis tests, and then estimates the best fitting model within the selected type. Such approaches ignore the uncertainty of the choice of extremal type on the subsequent inference. We overcome these deficiencies by applying the Bayesian inferential framework to an extended model which explicitly allocates a non-zero probability to the Gumbel type. Application of our procedure suggests that the effect of incorporating the knowledge of the Extremal Types Theorem into the inference for extreme values is to reduce uncertainty, with the degree of reduction depending on the shape parameter of the true extremal distribution and the prior weight given to the Gumbel type.     

协同创新视角下产学研合作行为决策机制研究

产学研合作是科技与经济结合的有效形式,协同创新理论对产学研合作提出了更高的要求。从协同创新视角出发,利用基于有限理性的演化博弈理论构建了企业与学研机构间的协同合作决策博弈模型,并对策略选择进行稳定性分析。理论研究和数值仿真结果表明:当企业和学研机构在协同合作中获得的经济收益净值大于其选择中途放弃获得的经济收益时,双方才会全部选择协同合作策略;产学研协同合作总收益、收益分配系数、赔偿系数和协同合作成本对企业和学研机构的决策结果有显著的影响,但作用机制有所不同;政府对产学研协同合作的资助和惩罚机制对企业和学研机构选择协同合作策略有促进的作用,但应将资助和惩罚力度控制在一定范围内发挥其最大激励效用。     

Permanence and extinction in competitive Lotka–Volterra systems with delays

In this paper, a class of competitive Lotka–Volterra systems are considered that have distributed delays and constant coefficients on interaction terms and have time dependent growth rate vectors with an asymptotic average. Under the assumption that all proper subsystems are permanent, it is shown that the asymptotic behaviour of the system is determined by the relationship between an equilibrium and a nullcline plane of the corresponding autonomous system: if the equilibrium is below the plane then the system is permanent; if the equilibrium is above the plane then this species will go extinct in an exponential rate while the other species will survive. Similar asymptotic behaviour is also retained under an alternative assumption.     

The beta stochastic utility (β-SU)

In this article, a new model for decision making under uncertainty is presented. Here, we model human attitude toward risks to show that an individual estimate of the expected utility of a lottery follows a generalized Beta distribution with a random error that follows a similar distribution. An individual is said to maximize his stochastic utility when requested to present his preference between risky lotteries. Hypothetically, risky lotteries are those exhibiting wider ranges of rewards where human estimate will not be below the utility of the lowest reward nor above the highest of the lottery. The Beta distribution is bounded and complies to such intuitive preconditions with a variance depending on such bounds. The proposed model will overestimate/underestimate the expected utility of a lottery according to the lottery probability mass and individuals' risk attitudes. By such estimation, our model conforms to the fourfold choice pattern. The model also explains the violations present as inconsistencies in the expected utility theory, such as Allais paradox, common consequence effect, common ratio effect, and the violation of betweenness that can be found in the fourfold choice pattern. For the validation purposes, 13 datasets from literature were collected and tested. The β-SU model fits the data at least as good as other approaches such as the CPT/StEUT and presents higher prediction log-likelihoods and less sum of squared errors in most of the cases, a matter that supports the proposition that human estimates of the expected utility may be drawn out of a generalized Beta distribution.     

Do internal controls improve operating efficiency of universities?

Improving operating efficiency is one objective of internal controls (IC). This paper investigates the relationship between IC implementation and operating efficiency of universities. Using data from questionnaire survey and from the field, this study measures IC implementation and applies data envelopment analysis to estimate operating efficiency of 99 universities in Taiwan. The OLS regression results indicate that IC implementation has an insignificant association with teaching-related efficiency, but has a negative and significant association with research-related efficiency. Dividing the sample into public and private universities, the analysis indicates that for public universities, IC implementation has no significant association with any of the two measures of efficiency. But, for private universities, there is a positive and significant association between IC implementation and teaching-related efficiency. The association between IC implementation and research-related efficiency is negative and significant.     

Rational modelling in understanding and aiding human decision-making: About two case studies

The last few years have brought a large movement of interrogating issues concerning the role and image of Operations Research. But, as a matter of paradox, the ‘OR crisis’ gives a better understanding of the role of rational modelling in choice processes and decision making. Rational models are a mean for conceiving idealised behaviour—rational myths—in structured situations; they are not first of all destined to be implemented or applied; they are the reference against which the analyst confronts the observed behaviour of specified actors.This confrontation permits the analyst to build with these actors a new vision of the constraints and objectives in which they operate. The resulting organisational dynamics are the soundest basis for evaluating the efficiency of this process.It is argued that the underlying mechanism of this learning process can be generally specified as a ‘tool-structure interaction’. These concepts describe a possible bridge between OR and organizational studies; it may lead to a renewed research in Management Science, avoiding the known pitfalls of these fields, when considerated separately in practice or in training.These points will be illustrated by the help of two cases studies concerning respectively scheduling problems in a job-shop and risky decisions in oil production investments.     

Delayed perfect monitoring in repeated games

Delayed perfect monitoring in an infinitely repeated discounted game is studied. A player perfectly observes any other player’s action choice with a fixed and finite delay. The observational delays between different pairs of players are heterogeneous and asymmetric. The Folk theorem extends to this setup. As is shown for an example, for a range of discount factors, the set of perfect public equilibria is reduced under certain conditions and efficiency improves when the players take into account private information. This model applies to many situations in which there is a heterogeneous delay between information generation and the players’ reaction.     

Pricing and logit-based mode choice models of a transit and highway system with elastic demand

The objective of this paper is to enhance the insights into transport pricing mechanism and the corresponding mode choice behavior in a simple bi-modal transportation system with elastic demand. This system comprises a mass transit parallel to a bottleneck-constrained highway between a residential area and a workplace. We derive and compare three pricing schemes: the arbitrarily fixed pricing, the first-best pricing for a social optimum of the system, and the second-best pricing in the case of incapability of road toll. It is shown that the first-best pricing requires to implement a road toll and a transit fare simultaneously, and the optimal transit fare for the second-best solution should be set to be a weighted sum of the marginal external costs between auto and transit commuters. A numerical example is presented to illustrate how the pricing policies affect the demand implementation, the mode choice behavior and the efficiency of the whole transportation system.     

Equity,efficiency and rights in social choice

The impossibility of a Paretian liberal presented by Sen shows the incompatibility of the Pareto principle with a mild claim of libertarian rights when they are required of the collective choice rule with unrestricted domain. In view of the profound implications of this paradox, it is no wonder that there are many serious attempts in the literature to seek for a general resolution thereof. In this paper, we try to explore an avenue which has been left relatively less cultivated in the attempts to try to find a way out of this paradox, the essential idea thereof being to restrict the ‘legitimate’ exercise of the liberatarian rights by the claims of justice or equity. It will be shown that the gist of the successful resolution of the Pareto libertarian paradox along this line lies in the impartiality of the principle of justice held by the individuals and the prevalence of the sympathetic acceptance of each other's subjective preferences.     

公众参与下中央与地方政府环保行为演化博弈研究

在公众参与背景下,构建有限理性条件下中央政府与地方政府的环境保护演化博弈模型,分析公众参与下双方环境保护策略选择。结果表明,中央政府严格监管的成本和收益、环保不作为对地方政府声誉的负面影响、地方环保投入和收益、被公众揭发的可能性等是影响双方行为的重要因素。中央监管收益的增加、成本的下降,有助于提高中央政府监管的积极性;地方不作为对地方声誉影响越大、收入分成越少,是提升地方政府努力的有效手段;公众的积极参与,是破解信息不对称,督促央-地政府采取积极环保措施的重要手段。最后,结合理论分析和实际,提出保障地方政府努力开展环保工作的措施。     

公交服务治理模式的效益比较研究

公交服务的市场化改革需要选择合理的治理模式以应对产生的种种问题,各模式间的效益比较就成为选择的关键因素。在理论比较PPP模式和网络治理模式的基础上,本文以PPP模式为参照对象,假定公交服务参与主体平等的合作,从各主体的控制权分配、努力水平和产出效率构建公交服务总效益模型,并进行了模型的理论分析和数据模拟,结果表明:总效益与各方主体的努力水平、控制权和产出效率紧密相关,仅当政府和社会群体间的边际成本替代率在合理范围内时,网络治理模式的总效益大于PPP模式,当超出合理范围时会使前者小于后者。     

延迟效应影响下的产学研协同创新知识共享研究

在高校和企业组成的产学研协同创新知识共享体系中,考虑成员的知识共享策略均存在延迟效应时的影响,构建了基于双延迟效应的动态微分模型。运用极大值原理,得到了协同创新主体在集中和分散两种决策下的最优知识共享策略、最优收益和体系的知识水平。研究发现:延迟时间的存在对高校和企业的知识共享策略具有负面效应,且均低于发生即时效应的情形;集中式决策并不总是优于分散式决策,两个延迟时间在满足一定的条件时,选择集中式决策为最优,否则双方企业将追求自身利益最大化而选择分散式决策;分散决策下,利润分配比例达到一定条件时,企业才愿意为高校提供补贴。且高校的知识共享延迟时间增加时,企业将提高该补贴比例。补贴比例越大,高校的知识共享水平越高,但对企业的知识共享策略没有影响。