Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

中间选民理论在农民工市民化政策制定中的运用——基武汉市436位农民工的实证研究

The Median Voter Theory is an important theory in the neo-political economics. It can be applied to solve the collective choice paradox and analyze the policy making for the citizenization of peasant workers. Adopting the method of factor analysis, this paper makes an empirical study on peasant workers’ preference for citizenization. We find that there is a paradox of future residence preference and self-identification in peasant workers. On this basis, peasant workers are divided into 5 subgroups, and it is found that the median undecided peasant workers are the median voters. Based on the analysis of the median undecided peasant worker’s complaints and appeals, it is proposed that the country should strengthen the vocational training system, establish a social security system, expand the agricultural reform and promote educational reform to facilitate the citizenization of peasant workers. __________ Translated from Guanli Shijie 맜理世界 (Management World), 2007, (4): 40–67     

绿色通道规划研究进展评述

有关绿色通道的理论及应用是近年来国内外景观设计学等领域研究的热点。从生态保护、历史文化保护、视觉美学评价、综合型绿道规划思想与方法、使用格局与体验、实施和管理及与相关政策的关系、各国绿道建设与发展情况七方面回顾与评述了绿色通道研究的进展,介绍了这一思想在我国的应用与发展,并对其研究与应用前景进行了展望。     

Group decision-making: Head-count versus intensity of preference

This paper puts forth a framework for reshaping the group decision-making process. The proposed framework extends from the usual one-issue-at-a-time decision-making to one that involves several related issues simultaneously. Weaknesses of the traditional majority voting mechanism are first identified, and then a different voting method that takes each individual voter's sentiment into account is discussed. Specifically, a decision-maker is asked to express his/her intensity of preference for the issues encountered. Three hierarchical structures—benefits, costs, and risks—are developed to evaluate the alternatives. Due to the nature of pairwise comparisons and synthesis, the proposed method is amenable to consensus building and has higher reliability and consistency. It can be used for candidate selection, e.g. governmental election, when a large population is involved. It is also effective for resource allocation and prioritization when a small group or business is concerned. We believe the proposed approach has potential for resolving deficiencies of the conventional voting mechanism, and can be applied to many real-world problems. Its implementation on the Internet is also discussed.     

浅析中国传统民居所反映出的家文化偏向

对我国传统民居所反映出的家文化偏向进行了深入系统的分析,并归纳出下面几点结论:传统民居选址、布局的风水模式,反映出了一种家之环境文化偏向;传统民居的对称组群封闭式布局,反映出了一种家之伦常文化偏向;传统民居材质的“当下存在”和祠堂的“永存不灭”,反映出了一种家之“弃祈”文化偏向。     

Completing the State Space with Subjective States

We define an opportunity act as a mapping from an exogenously given objective state space to a set of lotteries over prizes, and consider preferences over opportunity acts. We allow the preferences to be possibly uncertainty averse. Our main theorem provides an axiomatization of the maxmin expected utility model. In the theorem we construct subjective states to complete the objective state space. As in E. Dekel et al. (Econometrica, in press), we obtain a unique subjective state space. We also allow for preference for flexibility in some of the subjective states and commitment in others. Journal of Economic Literature Classification Number: D81.     

贴现因子、偏好和行为经济学

本文讨论了影响人们跨时选择的重要因素--贴现因子的最新进展以及他们在经济学和金融中的重要应用,给出了目前关于改变贴现因子的模型.     

基于时空路径的城市绿地享用公平性 研究——以成都市新、旧城区为例

从时空间行为视角切入，采用居民活动日志搜集成都市新、旧城区的绿地使用者时空路径数据集，辨识不同时间预算人群的潜在可用绿地分布及人群特征，并通过构建绿地时空享用量模型，从时空制约角度对成都市新、旧城区的绿地享用公平性展开分析。研究结果显示：1)成都市新、旧城区的绿地享用格局在辐射范围、享用强度和人群绿地享用时间预算方面具有时空间分异特征；2)日常出行链中固定性活动占比会对人群绿地享用时间预算产生影响；3)随个体时间预算不断被固定性活动所挤占，长距离通勤加班族、担负接送小孩上学的上班族等时间短缺型群体的绿地享用机会被深度制约，日益成为潜在的绿地享用弱势群体，在时间短缺型群体的潜在活动路径范围内增加绿地供给，有利于提高此类人群享用绿地的机会，从而提高片区的整体绿地享用公平性。     

“中国丹霞”福建泰宁世界自然遗产地社区居民点发展模式评价模型研究

为科学优选自然保护地社区居民点发展模式，构建客观评价模型对社区居民点发展模式进行定量评价显得尤为重要。基于“中国丹霞”福建泰宁世界自然遗产地9个社区居民点的调研数据，采用序关系分析法，以居民点人口结构、居民点景观风貌与传统文化、居民点产业发展模式，以及居民点位于遗产地的位置4个一级指标和相应二级指标为评价准则，构建该遗产地社区居民点发展模式优劣评价模型。研究表明，该遗产地9个社区居民点发展模式中，4个为疏解型，3个为搬迁型，2个为控制型，没有发展型。研究结果可为该遗产地社区居民点科学遴选发展模式提供定量评价依据，也可为生态价值高的自然保护地社区居民点发展模式的遴选提供参考。     

公众参与城市绿色空间管理维护 ——以坦纳斯普瑞公园为例

“公众参与”广泛应用于以美国为代表的西方现代景观规划设计领域。随着社会的发展在美国等国相继出现“公众参与”城市绿色空间管理维护的趋势，人们逐渐意识到管理维护对城市绿色空间的重要性。以美国波特兰市坦纳斯普瑞公园为典型案例，通过实地调查、文献研究、访谈、归纳推理等研究方法，从公园建设背景、设计特色出发，回顾“公众参与”前管理维护的困境，阐述“朋友和伙伴”项目的发展历程、工作内容及成效，总结“公众参与”后期维护管理的意义，分析成功推行的原因。“公众参与”有助于解决目前中国城市公园管理维护面临的投入资金不足、游人素质偏低等问题，对未来城市公园管理工作的发展具有重要启示意义。