Efficient Facet Based Efficiency Index: A Variable Returns to Scale Specification

The appearance of strictly positive slack variables in DEA solutions causes well known computational and analytical problems studied by Olesen and Petersen (1996) and Green et al. (1996) under constant returns to scale. This paper discusses variable returns to scale and suggests the use of efficient facets (EFs) in the reference technology. It is found to give a lower bound of the efficiency scores. Most importantly, efficiency measured with respect to EFs—the EF based efficiency index—may decrease if additional variables are introduced but are disposed in production. Thus, units are penalized for disposal of incoming variables, and the EF based efficiency index captures the net efficiency of a unit. EF is found to be a useful tool also to search a suitable set of variables for efficiency measurement. Its use is demonstrated with Finnish university data and it is found to change the measured performance of the university sector quite significantly.     

北京市生态足迹的投入产出分析

生态足迹是可持续发展最重要的测度指标之一.本文将投入产出分析技术引入生态足迹模型,使用北京市2005年投入产出延长表等数据衡量了北京市的可持续发展状况.结果表明:北京市2005年生态足迹总需求为3853.8万公顷.约为北京市土地总面积的23倍;人均生态足迹为2.51公顷,高于其生态承载力.北京的经济发展尚处于不可持续状态.     

Market‐oriented institutions and policies and economic growth: A critical survey

Abstract.  This paper surveys recent evidence suggesting that market‐oriented institutions and policies are strongly related to economic growth, focusing on studies using the economic freedom (EF) indicator of the Fraser Institute. This index is critically discussed. Also various serious shortcomings of empirical studies using this index are identified. Nevertheless, there are strong indications that liberalization, i.e. an increase in the EF index, stimulates economic growth. This paper also reviews studies on the determinants of EF. Political liberalization is often found to enhance economic liberalization, whereas there is less evidence for causality running in the other direction.     

A characterization of the nonlinearity of d-stability

A set of equilibrium prices in a multiple commodity market is stable regardless of the adjustment rates in each market if and only if the Jacobian of the system is D-stable. In this note we show that a stable matrix is D-stable if and only if a certain pair of simultaneous nonlinear equations does not have a common zero over the range of positive n-vectors.     

Validating innovating practice and perceptions of course management system solutions using structural equation modeling

As adopting information and communications technology to deliver instruction and facilitate learning, course management systems (CMSs) offer an alternative capability to enhance management practices. Based on innovation diffusion theory, this study explores CMS effectiveness (EF) and reliability (RL), and considers both perceived innovative attributes (IA) and demographic characteristics. This study also exams the moderating effect of complexity (CX) and mediating effect of function evaluation (FE) on the causal relationship between IA and outcome variables (i.e., EF, RL). Analysis also includes the differential effects of three types of CMSs and gender differences. Participants were 238 undergraduates, majored in business or management, who volunteered to complete an online survey. Results show that perceived IA affect RL and EF, but not FE. CX moderates the effect of perceived IA on RL, but does not moderate the effects of perceived IA on FE and EF. EF, but not FE, appears to mediate the effects of perceived IA on RL. There is no significant difference in model fit between genders, but there is among the type of CMS solution group. Conclusions and implications are offered regarding the future research for program leaders and practitioners.     

The local stability of an open-loop Nash equilibrium in a finite horizon differential game

We propose a finite time differential game as a model for some economic processes and derive conditions for the Nash equilibrium solution to be locally asymptotically stable. We adopt the traditional ‘Cournot-reaction function’ notion of stability, which in our (continuous time) model becomes a function-to-function, or trajectory-to-trajectory, mapping. The conditions for stability seem to make economic sense. The equilibrium is less stable if the interaction terms in each period are large, if the game has a long duration, and if the discount rate is small.     

Are hyperinflation paths learnable?

Earlier studies of the seigniorage inflation model have found that the high-inflation steady state is not stable under learning. We reconsider this issue and analyze the full set of solutions for the linearized model. Our main focus is on stationary hyperinflationary paths near the high-inflation steady state. These paths are shown to be stable under least-squares learning if agents can utilize contemporaneous data. In an economy with a mixture of agents, some of whom only have access to lagged data, stable hyperinflationary paths emerge only if the proportion of agents with access to contemporaneous data is sufficiently high.     

Sales-optimization under an unstable profit-constraint

This paper considers a firm's manager who maximizes total sales under unstable profit-constraint. It is proved that, even if being risk-neutral, the manager is worse off than in the stable equivalent case and that his best policy is to produce less than in the stable case.     

Strategy-proofness in many-to-one matching problems

We search forstrategy-proof solutions in the context of (many-to-one) matching problems (Gale and Shapley, 1962). In this model, whenever the firms can hire as many workers as they want (the capacities are unlimited) the stable set is a singleton. There exists aPareto efficient, individually rational, andstrategy-proof matching rule if and only if the capacities are unlimited. Furthermore, whenever the capacities unlimited, the matching rule which selects the unique stable matching is the only matching rule that isPareto efficient, individually rational, andstrategy-proof.     

Partnership-enhancement and stability in matching problems

In two-sided matching problems, we consider “natural” changes in preferences of agents in which only the rankings of current partners are enhanced. We introduce two desirable properties of matching rules under such rank-enhancements of partners. One property requires that an agent who becomes higher ranked by the original partner should not be punished. We show that this property cannot always be met if the matchings are required to be stable. However, if only one agent changes his preferences, the above requirement is compatible with stability, and moreover, envy-minimization in stable matchings can also be attained. The other property is a solidarity property, requiring that all of the “irrelevant” agents, whose preferences as well as whose original partners’ preferences are unchanged, should be affected in the same way; either all weakly better off or all worse off. We show that when matchings are required to be stable, this property does not always hold.     

The Blocking Lemma for a many-to-one matching model

The Blocking Lemma identifies a particular blocking pair for each non-stable and individually rational matching that is preferred by some agents of one side of the market to their optimal stable matching. Its interest lies in the fact that it has been an instrumental result to prove key results on matching. For instance, the fact that in the college admissions problem the workers-optimal stable mechanism is group strategy-proof for the workers and the strong stability theorem in the marriage model follow directly from the Blocking Lemma. However, it is known that the Blocking Lemma and its consequences do not hold in the general many-to-one matching model in which firms have substitutable preference relations. We show that the Blocking Lemma holds for the many-to-one matching model in which firms’ preference relations are, in addition to substitutable, quota q-separable. We also show that the Blocking Lemma holds on a subset of substitutable preference profiles if and only if the workers-optimal stable mechanism is group strategy-proof for the workers on this subset of profiles.     

On stable rules for selecting committees

A voting rule is said to be stable if it always elects a fixed-size subset of candidates such that there is no outside candidate who is majority preferred to any candidate in this set whenever such a set exists. Such a set is called a Weak Condorcet Committee (WCC). Four stable rules have been proposed in the literature. In this paper, we propose two new stable rules. Since nothing is known about the properties of the stable rules, we evaluate all the identified stable rules on the basis of some appealing properties of voting rules. We show that they all satisfy the Pareto criterion and they are not monotonic. More, we show that every stable rule fails the reinforcement requirement.     

Imitation and price competition in a differentiated market

We study the stable market outcome that evolves in a spatially differentiated market when price-competing firms choose actions by imitation of the most profitable firm. We compare and contrast the stable outcomes under two imitation procedures: one, where each firm immediately imitates the most profitable firm, and the other when a firm imitates another firm only if it is more profitable while being “sufficiently similar” (in context of the market segment it operates in) or “sufficiently close”. In either case, the symmetric pure strategy Nash equilibrium is always a stable outcome. However, when imitation of the most profitable firm is immediate and market differentiation is ‘moderate’, states with prices lower than the Nash equilibrium are also stable. In contrast, when imitation of the most profitable firm is more gradual and market differentiation is below a threshold, states with prices above the Nash equilibrium are also stable. Thus, while competitive evolutionary pressure in this imitation based model does result in the Nash equilibrium always being stable, other outcomes may be stable as well. Interestingly, the states that are stable under gradual imitation give the firms a higher profit than the stable states under immediate imitation.     

Two-sided matching with spatially differentiated agents

We consider the problem of assigning sellers and buyers into stable matches. The agents are located along a line and the match surplus function is decreasing in the distance between partners. We investigate the structure of stable assignments under both non-transferable utility (NTU) and transferable utility (TU). If the surplus function is sufficiently convex, the TU-stable assignments are a subset of the NTU-stable assignments. Furthermore, if trade is restricted to uni-directional flows the unique TU-stable assignment coincides with the unique NTU-stable assignment for every convex surplus function. We also examine the graph-theoretic representation of stable assignments and show that the graph structure can be exploited to compute surplus shares in TU-stable assignments.     

A note on “Evolution of Preferences”

A surprising result in Dekel et al. (2007) states that strict Nash equilibria might cease to be evolutionary stable when agents are able to observe a signal that fully reveals the opponent’s preferences, even if the frequency of the signal is very low. I show that when the signal a player receives on her opponent’s preferences is almost uninformative, all strict Nash equilibria are evolutionary stable, no matter the frequency of the signal.     

Farsighted house allocation

In this note we study von Neumann–Morgenstern farsightedly stable sets for Shapley and Scarf (1974) housing markets. Kawasaki (2010) shows that the set of competitive allocations coincides with the unique von Neumann–Morgenstern stable set based on a farsighted version of antisymmetric weak dominance (cf., Wako, 1999). We demonstrate that the set of competitive allocations also coincides with the unique von Neumann–Morgenstern stable set based on a farsighted version of strong dominance (cf., Roth and Postlewaite, 1977) if no individual is indifferent between his endowment and the endowment of someone else.     

Robustness of stable volatility strategies

The paper analyzes the robustness of stable volatility strategies, i.e. strategies in which the portfolio weight of the stock is inversely proportional to its local volatility. These strategies are optimal for a CRRA investor if the stock follows a diffusion process, the expected excess return is proportional to its volatility, and the hedging demand is zero. We assess the performance of stable volatility strategies when these restrictive assumptions do not hold, in particular, when the risk premium is not proportional to volatility and when the stock price is subject to jumps. We find that stable volatility strategies are indeed robust or close to robust under a maxmin decision rule. In addition to our theoretical results, we perform a simulation analysis to evaluate strategies that scale the portfolio weight by the volatility, variance or a constant portfolio weight, and also analyze the strategies using empirical excess returns. Both analyses confirm the robustness of stable volatility strategies.     

ISO9000族标准如何引入独立学院管理中初探

独立学院是顺应中国经济社会发展的迫切需要,在特定的历史背景下产生的新型大学,ISO9000族标准若能结合独立学院实际引入到独立学院管理中将系统的解决各个环节的管理问题最终保障保障独立学院健康、稳定可持续发展。     

Common factors can always be found but can they also be rejected?

Factor models are often used to reduce the complexity of data. It is simple to find common factors and to interpret them. However, it is doubtful whether factor models are always appropriate. Especially when the common factor is considered to be an attitude, it must be stable through time and explain a considerable part of the variances. A procedure is suggested to test the usefulness of a common factor. In an experimental pilot study in which an attitude towards immigrant workers was investigated, the instability and superfluousness of a common factor is shown. An alternative model is presented which suggests that changing opinions can be explained by specific variables. Finally it is shown that a more stable common factor is found if a so-called MIMIC-design is used.     

变电站互感器二次回路误接线反事故措施的探讨

互感器是电力系统的重要组成部分,其能否正确发挥作用对电力系统的安全稳定运行关系重大,分析互感器二次回路误接线的原因,提出防止互感器二次回路误接线的反事故措施,以提高继电保护及自动装置的安全可靠运行水平。