A model of price and quantity adjustments in primary commodity markets

This paper presents a dynamic, simultaneous model of price and quantity adjustments in world primary commodity markets. The model is formulated in a disequilibrium framework, emphasizing particularly the role of price adjustment. In addition to the price equation, commodity consumption and production equations are also specified. The empirical analysis of the model is carried out with the annual data of six primary commodities: coffee, cocoa, rubber, copper, tin, and sugar. This includes the estimation of price, consumption, production equations, the simulation tests of complete structural models for these six commodities, and the derivation of dynamic responses (measured by elasticities) of commodity prices to changes in world income, world inflation, and commodity outputs. Dynamic simulations strongly confirm the commonly observed self-generating and recurring boom-and-bust cycles of primary commodity prices. This finding lends credibility to the models constructed.     

关于闽南语皮（纸）影戏本的研究——读《欧洲汉学研究会不定期刊》第2辑

<欧洲汉学研究会不定期刊>(Occasional Pagers,European Association of Chinese Studies)第2辑(1979),收入了施博尔(施舟人)、饶宗颐、龙彼得三教授研究闽南语皮(纸)影戏本的学术经典之作.施博尔(施舟人)、饶宗颐、龙彼得三教授的参与,提升了闽南语皮(纸)影戏本之研究的学术水准,海峡两岸学者当继续戮力推展此一高水准的学术研究工作.     

Fertility rates and skill distribution in Razin and Sadka’s migration-pension model: A note

Razin and Sadka (1999) show that unskilled immigration is beneficial to all income and all age groups in society, even if immigrants are net beneficiaries of the welfare system. Among other things, this result rests on the assumptions that immigrants have the same reproduction rate as the native population and that the immigrants offspring has the same distribution of skills as the natives offspring. By relaxing these assumptions, we show that the Razin and Sadka result is no longer unambiguous.Helpful comments and suggestions from two anonymous referees are gratefully acknowledged. Responsible editor: Alessandro Cigno.     

一类证券组合投资问题的H∞状态反馈投资策略

为研究兼顾实际系统离散性和参数时变性的证券组合投资问题,提出了一个衡量风险大小的二次型性能指标,并建立了证券组合投资的离散时变状态空间模型.运用离散时变系统的H_∞控制理论,得到了证券组合投资的H_∞状态反馈投资策略.仿真证明使用该投资策略可使总收益实现其最小的不确定性.     

股票收益分散度的不对称性研究——基于A+H股的实证检验

以A+H股为样本,以横截面收益离差绝对值作为收益分散度的代理指标,对A股市场和H股市场的对比研究发现:在A股市场存在收益分散度的不对称性,即在上涨市场中股票收益的分散度低于下跌市场。按A股市值大小分组后发现:收益分散度的不对称现象在小市值股票中更加严重。A股市场中主力投资者和散户投资者在趋势交易过程中的博弈行为可能是导致这一现象的原因。     

Social security,social welfare and the aging population

This study examines the effects of pay-as-you-go social security programs in aging economies when the middle-aged both educate their dependent children and subsidize the retirement of the old. Using an overlapping generations framework in which agents are three-period lived but timing of death in the third period is uncertain, we analyze the effects of social security tax schemes, under various demographic assumptions, on capital accumulation, education expenditures, social welfare, and economic growth. We find that in many cases social security crowds out education, and reduces economic growth and social welfare. Received: 29 April 1998/Accepted: 3 March 1999     

Accuracy of regularized D-rule for binary classification

We consider a regularized D-classification rule for high dimensional binary classification, which adapts the linear shrinkage estimator of a covariance matrix as an alternative to the sample covariance matrix in the D-classification rule (D-rule in short). We find an asymptotic expression for misclassification rate of the regularized D-rule, when the sample size $n$ and the dimension $p$ both increase and their ratio $p∕n$ approaches a positive constant $\gamma$. In addition, we compare its misclassification rate to the standard D-rule under various settings via simulation.     

The twin deficit hypothesis in Egypt

We employ a new approach to the twin deficit hypothesis aimed at enhancing policy making in Egypt. In contrast to the conventional twin deficit hypothesis between the current account, which comprises many items out of governments’ scope of maneuvering, and the budget deficit, we track the causal link between Egypt’s merchandise trade deficit and the budget deficit. We begin first by examining the conventional twin deficit hypothesis using a VAR model, which implies short run reverse causation running from the current account deficit to the budget deficit. Second, as cointegration exists between the budget deficit and the merchandise trade deficit, we run a multivariate VECM model which refutes the twin deficit hypothesis in favor of the current account targeting hypothesis. In policy terms, ameliorating Egypt’s trade balance would ultimately improve its fiscal balance as well.     

改革开放后俄罗斯文学在中国传播发展的新变化——基于拉斯维尔“5W”模式的阐释

自新中国成立以来,俄罗斯文学在我国的传播发展已走过了60多年艰难曲折的历程.在其整个传播发展过程中,改革开放这一重要历史事件对于俄罗斯文学的传播发展产生了重大影响.文中将以传播学的“5W”模式作为研究视角,从传播主体、传播对象、传播内容、传播手段以及传播效果5个方面,对改革开放前后俄罗斯文学在中国的传播活动进行研究分析,进而揭示改革开放后俄罗斯文学的传播发展所产生的新变化,为进一步开展对俄罗斯文学的研究提供参考.     

三种股利分配方案对股价影响差异性的实证研究

股利政策是公司重大财务决策之一,上市公司的股利分配方案公布会引起二级市场股票价格的波动。目前,我国上市公司实际采用的股利分配方案中,主要包括现金股利、股票股利和不分配三种。研究股利分配政策,从而改变企业资本结构,对了解二级市场股价波动及公司并购具有很强的意义。