进攻崇拜:一个理论神话的破灭

攻防理论认为,第一次世界大战前的军事技术发展有利于防御,但欧洲大国却误判为进攻主导,因此它们均采取进攻性战略,并导致一战的悲剧性爆发。事实并非如此。一战前的德国军事家十分认真地研究过新型武器的防御效果,承认它们会形成战术层面上的防御主导,但他们否认这是不可逾越的障碍,并致力于通过战术和战略创新来恢复进攻的可能。因此,战术层面上的防御占优会增加战争的难度和参战国的成本,但绝不会使发动战争在军事上变得不可能。攻防理论中暗含的军事技术决定战争爆发论的失败就在于它忽视了武器与人相结合的困难,想当然地简化了军事技术与军事组织相结合的过程。实际上,军事技术只是一种结构性限制框架,并不直接或必然驱使国家采取适应某种军事战略。人类可以发挥主观能动性来克服武器的防御特性,从而恢复进攻的可能性。战争从来就是敌我双方智慧与力量的博弈,绝非由某一类武器决定。     

超竞争环境下电信运营商竞合策略研究

目前,我国电信行业面临着超竞争态势,其电信市场上表现出显性的同质竞争及隐性的异质竞争。在这样的环境下,国内电信运营商很难适应,无法满足用户个性化、多样化的新需求。为此,国内三大电信运营商必须加强相互间的合作,找到竞争与发展的平衡点,只有这样才能使我国的电信行业可持续健康发展。     

The Neglected Institutionalism of Wesley Clair Mitchell: The Theoretical Basis for Business Cycle Indicators

Addressing the question why Economics as a discipline is not subject to evolutive processes itself, we explain the paradigmatical dominance of neoclassical theories in Economics as a path dependent process. Recognizing economics as "locked into neoclassical thinking," we first identify three positive feedback mechanisms leading to strong barriers to paradigmatic change: coordination, complementarity, and learning mechanisms. In a second step, we show how actors strategically enforce these mechanisms via distinct "amplifiers." We then try to use this theoretical perspective to cursorily describe potentially path-breaking strategies.     

基于ANP的国有森工集团经营绩效监测研究

首先构建了国有森工集团经营绩效监测体系,确定了经营绩效监测方法,应用ANP确定了监测指标的优势度;然后通过实证分析,输出龙江森工集团经营绩效的监测结果,对经营绩效进行综合评价。研究结果表明:第一,经营绩效监测指标体系中不同指标具有不同的优势度和贡献度,其协同作用反映了森工集团的整体经营绩效;第二,自天保工程实施以来(2001²011)龙江森工集团经营绩效呈现显著上升态势,企业整体生产运营健康、有序、稳固;第三,从经营绩效监测结果来看,国有森工集团森林旅游、林下经济等生态型特色优势产业发展取得积极进展,替代互补优势逐步显现。     

A General Theorem on the Comparative Statics of Changes in Risk

In this paper, the concept of absolutely riskier than is introduced to generalize Gollier's (Journal of Economic Theory, 66, 522–535) necessary and sufficient conditions for the comparative statics of a change in risk for risk averters. The restrictive assumption that the payoff function is monotonic in the risk is relaxed. The policymaker's choice problem, the newsboy problem, and a farmer's example are used to illustrate how easily the monotonicity assumption is violated. Finally, some important properties of the concept of absolutely riskier than, such as its relation with the concept of second-order stochastic dominance, are illustrated using the farmer's example.     

Robust optimization of forecast combinations

We develop a methodology for constructing robust combinations of time series forecast models which improve upon a given benchmark specification for all symmetric and convex loss functions. Under standard regularity conditions, the optimal forecast combination asymptotically almost surely dominates the benchmark, and also optimizes the chosen goal function. The optimum in a given sample can be found by solving a convex optimization problem. An application to the forecasting of changes in the S&P 500 volatility index shows that robust optimized combinations improve significantly upon the out-of-sample forecasting accuracy of both simple averaging and unrestricted optimization.     

我国城镇居民收入分配的变动趋势:基于社会福利比较的视角

经济学研究的出发点是社会福利的最大化.通过不断放松社会福利函数的约束条件,依次应用洛伦茨优势比较、广义洛伦茨优势比较、均值一方差优势比较和社会福利指数比较等社会福利比较准则,对1985～2004年期间我国城镇居民收入分配变动状况进行比较和排列,研究结果表明:除在1987～1989年期间城镇居民收入分配状况存在轻微社会福利恶化外,居民收入分配的社会福利水平一直呈逐年上升趋势,且在大多数年份中社会福利存在帕累托改善,社会福利改善的成因是实际收入的增长足以补偿收入不平等的扩大.     

风险变动对个人保险需求的影响——基于期望效用与均值-均方差的分析

风险是保险需求存在的前提,风险的变动会引起保险需求的变动.在期望效用(EU)框架下,根据不确定性的一些研究结论推知,风险增加将引起保险需求增加;在均值-均方差方法下,Battermann等人推导了风险增加、风险厌恶弹性和保险需求三者之间的关系,Thomas Eichner和Andreas Wagener证明,在风险分布之间具有线性关系的条件下,Battermann等人的结论在EU方法中也成立.笔者证明,只要随机变量的分布具有二阶占优,则该方法可以完全替代EU方法,从而Battermann等人的结论可以推广到分布族不同的风险决策中.     

The impact of prudence on optimal prevention

Summary. What are the determinants of the optimal level of effort to reduce the probability of a loss to occur? Whereas most of the literature on this question focused on risk aversion, we show that the concept of prudence (i.e., a positive third derivative of the utility function) is essential to answer this question. We explain in this paper that prudence and prevention tend to be opponents rather than allies contrary to the intuition attached to everyday language.Received: 7 November 2003, Revised: 3 August 2004, JEL Classification Numbers: D61, D81. Correspondence to: Christian Gollier