Through Trial and Error to Collusion*

In this article we study a very simple trial and error learning process in the context of a Cournot oligopoly. Without any knowledge of the payoff functions players increase, respectively decrease, their quantity as long as this leads to higher profits. We show that despite the absence of any coordination or punishing device this process converges to the joint‐profit‐maximizing outcome.     

毛泽东关于中国革命的科学预见及其重大意义

毛泽东具有高超的科学预见的能力。毛泽东的科学预见能力在于他掌握了社会调查的方法 ,正确地运用对立统一规律和量变到质变的规律 ,以及采取“从群众中来 ,到群众中去”的方法。学习毛泽东关于中国革命的科学预测理论与方法 ,对于处理当今国际国内的各种复杂问题有着十分重要的意义。     

乡镇企业如何创建和谐的劳动关系

乡镇企业劳动关系普遍不够规范、和谐,是制约乡镇企业进一步发展的重要因素之一。劳资双方的矛盾冲突内容广泛且积重难返。造成这一局面的原因既有乡镇企业先天不足、劳资双方人员构成及素质局限等原因,也有政府部门疏于管理监督和引导等原因。创建乡镇企业和谐劳动关系也应当对症下药,在法律、行政管理、企业内部管理机制、劳资双方素质提升等各方面采取有效对策。     

论教育与人和社会的发展

人的发展和社会的发展都是人类追求的目标。在充分发挥教育为社会政治、经济、文化服务的功能的时候,必须始终不要忘记贯彻教育是培养人、塑造人这个根本的功能;而教育培养人,必须从一定社会历史条件出发,在服务社会过程中逐步接近,直到最后实现这个目标。     

A theoretical framework to evaluate different margin‐setting methodologies

The margin system is the first line of defense against the default risk of a clearinghouse. From the perspectives of a clearinghouse, the utmost concern is to have a prudential system to control the default exposure. Once the level of prudentiality is set, the next concern will be the opportunity cost of the investors, because high opportunity cost discourages people from hedging futures, and thus defeats the function of a futures market. In this article, we first develop different measures of prudentiality and opportunity cost. We then formulate a statistical framework to evaluate different margin‐setting methodologies, all of which strike a balance between prudentiality and opportunity cost. Three margin‐setting methodologies, namely, (1) using simple moving averages; (2) using exponentially weighted moving averages; (3) using a GARCH approach, are applied to the Hang Seng Index futures. Keeping the same prudentiality level, it is shown that the one using a GARCH approach by and large gives the lowest average overcharge. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:117–145, 2004     

The index futures markets: Is screen trading more efficient?

This article uses a nonparametric test based on the arc‐sine law (see, e.g., Feller, 1965 ), which involves comparing the theoretical distribution implied by an intraday random walk with the empirical frequency distribution of the daily high/low times, in order to address the question of whether the abandonment of pit trading has been associated with greater market efficiency. If market inefficiencies result from flaws in the market microstructure of pit trading, they ought to have been eliminated by the introduction of screen trading. If, on the other hand, the inefficiencies are a reflection of investor psychology, they are likely to have survived, unaffected by the changeover. We focus here on four cases. Both the FTSE‐100 and CAC‐40 index futures contracts were originally traded by open outcry and have moved over to electronic trading in recent years, so that we are able to compare pricing behavior before and after the changeover. The equivalent contracts in Germany and Korea, on the other hand, have been traded electronically ever since their inception. Our results overwhelmingly reject the random‐walk hypothesis both for open‐outcry and electronic‐trading data sets, suggesting there has been no increase in efficiency as a result of the introduction of screen trading. One possible explanation consistent with our results would be that the index futures market is characterized by intraday overreaction. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:337–357, 2004     

An empirical analysis of the relationship between the hedge ratio and hedging horizon: A simultaneous estimation of the short‐ and long‐run hedge ratios

This article analyzes the effects of the length of hedging horizon on the optimal hedge ratio and hedging effectiveness using 9 different hedging horizons and 25 different commodities. We discuss the concept of short‐ and long‐run hedge ratios and propose a technique to simultaneously estimate them. The empirical results indicate that the short‐run hedge ratios are significantly less than 1 and increase with the length of hedging horizon. We also find that hedging effectiveness increases with the length of hedging horizon. However, the long‐run hedge ratio is found to be close to the naïve hedge ratio of unity. This implies that, if the hedging horizon is long, then the naïve hedge ratio is close to the optimum hedge ratio. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:359–386, 2004     

用诚信为社保铺路

失地农民生活到底怎么样?笔者近日对江苏省金坛市洮西镇近百户失地农民生活状况进行了调查。调查发现,有些失地农民早已经用完以前得到的土地补偿金。他们当中相当一部分人由于受文化、年龄等因素制约,一直没有稳定的务工岗位和收入来源,家庭生活困难。被调查的这百户失地农民,