Multi-valued strategy-proof social choice rules

In this paper we introduce a new definition of strategy-proofness for multi-valued social choice correspondences. We prove two Gibbard-Satterthwaite type results for strategy-proof social choice correspondences. These results show that allowing multiple outcomes as social choices will not necessarily lead to an escape from the Gibbard-Satterthwaite impossibility theorem. Received: 24 January 2001/Accepted: 19 March 2001     

四川城市灾害的预防与环境安全保护

开始于18世纪工业革命的城市化进程,到20世纪末21世纪初信息革命完成时达到高潮:21世纪将是一个城市化的世纪.随着城市化水平的提高,城市规模急骤膨胀、人口剧增、资源匮乏、环境污染、生态恶化,文化趋同,区域差距拉大,则出现了一系列城市与自然的对立不协调等问题,自然灾害频繁,灾害给城市经济造成的损失越来越大.在四川,1989年4月20日发生在泸州的风暴造成的直接经济损失计11亿元;2001年9月19日发生在绵阳、德阳的暴雨洪涝灾害给两市造成直接经济损失高达21亿元.灾害作为城市可持续发展的一个突出而紧迫的问题,越来越成为人们关注的焦点.     

滨海新区对外通道在促进区域发展中的作用

一、"三北"地区是滨海新区重要的服务区域 (一)滨海新区服务区域的界定 国务院20号文件将天津滨海新区定位为:"依托京津冀、服务环渤海、辐射‘三北'、面向东北亚,努力建设成为我国北方对外开放的门户、高水平的现代制造业和研发转化基地、北方国际航运中心和国际物流中心,逐步成为经济繁荣、社会和谐、环境优美的宜居生态型新城区."     

北京话的轻音和语法化

北京话是汉语发展变化最快的方言。北京话在语法化的过程中,轻音(包括轻声和语句轻音)是极为重要的形式标志和变化动因。本文就北京话轻音和语法化相关的问题作一些探讨,指出北京话构词后缀的产生、虚词的虚化都与轻音有着密切的关系。     

The effects of the age and structure of population on family change]

The age structure of a population is one basic factor of population research. It is not only affected by birth, death, immigration, and marriage, but it also reflected in changes of family size. The article analyzed it from two aspects: (1) the age structure of population acts on the size and structure of the family. The younger the age structure, the larger the family size. Otherwise, it is the opposite. According to the 1982 census, 35.4% of the population was 0-14 years in rural areas, and average family size was 4.6; but in urban areas 26.0% of the population was 0-14 years and family size was 3.9. The family was characterized as a nuclear family as industrialization in economic development increased and the population aged. In the 1982 census, 64.7% were nuclear family and 6% were aging population in China. Three- generation families (or more) have decreased dramatically. The change of family size and structure is affected by change of internal family age structure. The younger population (0-14 years) is dependent and 90% live with their parents. The adult population (15-59) years are more affected by marriage, birth and social economic action. Families are established in this age period and give much more effect to fertility. The aging population (over 60) years is facing changes. They appear to be a "Defect" family because the wife or husband has passed away. They change from independent to dependent. 78.3% population over 60 years were dependent on children or social welfare, only 21.7% were independent according to the survey in Beijing Changping County.     

Inefficiency of strategy-proof allocation mechanisms in pure exchange economies

In this paper I prove that in the standard model of 2×n (n2) pure exchange economies there is no allocation mechanism that is efficient, non-inversely-dictatorial, and strategy-proof. This strengthens two previous results on this subject by Hurwicz and by Dasgupta, Hammond, and Maskin.I thank Alvin Klevorick, William Thomson, and an anonymous referee of the journal for many helpful comments.     

中国共产党对社会主义本质理论的探索

社会主义本质是什么?马克思、恩格斯在创立科学社会主义理论的过程中,主要从与资本主义相比较的角度来揭示未来共产主义的一般特征。中国共产党对社会主义本质理论进行了艰辛探索,深刻回答了什么是社会主义这个根本问题,丰富和发展了社会主义本质理论。     

中小企业成长战略的探讨--江苏通润集团成长的个案分析

本文从江苏通润集团成长的历程探讨中小企业成长的机理.认为该集团的成长过程不仅是一个不断克服危机、积累资本的过程,而且还是一个捕捉机遇、培育核心能力的过程.通过对通润集团成长历程的剖析,揭示出中小企业成长的方式可以是多样的,企业资源的配置应在发展战略总目标的基础上,根据具体的环境变化来进行;说明了企业战略、产业转移与成长密切的相互关系以及培育企业核心能力的策略性步骤,为中小企业在经济全球化条件下的成长方式提供了可资借鉴的案例.