上海A股市场股价波动相互影响能力实证研究

股票市场中股票价格的波动是相互影响的,但不同的股票其价格波动时对其他股票价格行为的影响能力是不同的。本文通过对我国上海A股市场的实证分析表明,有少数股票其价格波动时对其他股票价格行为有很强的影响能力,而大多数股票的这种影响能力很小。此外,单个股票价格波动时引起其他股票价格涨、跌的能力一般都有显著差异。     

World Oil Depletion Models: Price effects compared with strategic or technological interventions

World oil depletion, including natural gas liquids, was modelled in the past by many authors. Recently, Guseo and Dalla Valle have introduced and Guidolin has applied a new approach following perturbed life-cycle diffusion models. Here we examine joint effects of economic and strategic or technological interventions using a Generalized Bass Model (GBM). Statistical analysis takes into account three different hierarchical levels: natural diffusion, long memory interventions and stochastic components. The main results confirm the statistical significance of historical 1970s shocks and highlight a strong long memory effect due to an increase in oil production after World War II. The estimated peak-date, 2007, and the 90% depletion time, 2019, are determined under an equilibrium intervention hypothesis.     

On strategic complementarity conditions in Bertrand oligopoly

Summary. For Bertrand duopoly with linear costs, we establish via a single (counter-)example that: (i) A new monotone transformation of the firms' profit functions may lead to the supermodularity of transformed profits when the standard log and identity transformations both fail to do so, and (ii) Topkis's notion of critical sufficient condition for monotonicity of a Bertrand firm's best-reply correspondence cannot be extended to rely only on positive unit costs. Received: January 16, 2001; revised version: March 20, 2002 RID="*" ID="*" This work was completed while the first author was visiting the Institute for Industrial Economics at the University of Copenhagen during Spring 2000. Their financial support and stimulating research environment are gratefully acknowledged. The views expressed here are those of the authors and should not be attributed to the European Commission. Correspondence to: R. Amir     

旅行社价格战的博弈分析

旅行社是旅游产品设计、组织和销售的渠道商以及消费者之间的桥梁.旅行社对旅游业具有重要影响，旅行社之间的价格竞争日益严重，盈利率低。随着我国加入世贸组织，越来越多的外国旅行社进入我国、针对我国旅行社如何走出困境，本文从博弈角度分析旅行社的价格竞争及其对策。     

Government as a discriminating monopolist in the financial market: the case of China

We show that the many unusual features of China’s financial markets are consistent with a government choosing regulations to maximize a standard type of social welfare function. Under certain conditions, these regulations are equivalent to imposing explicit taxes on business and interest income, yet should be much easier to enforce. The observed implicit tax rates are broadly in line with those observed in other countries. The theory also forecasts, however, that China will face increasing incentives over time to shift to explicit taxes.     

投资与通货膨胀-紧缩的联系:来自中国的经验证据

基于Toda-Yamamoto长期因果检验程序和广义脉冲反应技术,本文首先研究了全社会实际固定资产投资与零售价格水平变动之间的长期因果及其冲击-动态反应关系,然后进一步考察了货币供给量M1和贸易依存度在促成上述关系中所扮演的角色.其研究结论为:(1)货币供给量M1是唯一的外生变量,其增长不是价格水平变动的直接因,而是通过全社会实际固定资产投资间接地成为价格水平变动的因;(2)贸易依存度和全社会实际固定资产投资之间存在双向因果联系,前者只能通过后者间接地成为价格水平变动的因;(3)中国对外开放既消化又强化了中国生产能力过剩,但消化胜于强化;(4)投资一个单位正向冲击在开始的2-4年左右导致相对温和的通货膨胀,但后五年左右将导致相对严重的通货紧缩.     

价格歧视战略与福利效应分析

在完全竞争市场条件下 ,竞争均衡可实现帕累托最优效率。垄断市场一般很难提供价格等于边际成本的产量水平 ,其产量与价格选择对社会来说不是最优的。垄断厂商以内生范畴和外生范畴为基础对消费者进行分类 ,使得价格歧视成为一种可行战略。由于定价策略存在差异 ,不同类型的价格歧视便具有不同的福利效应。     

价格涨跌幅限制起到了助涨助跌作用吗?

价格涨跌幅限制是否具有助涨助跌作用对于判断涨跌幅限制的实施效果具有重要的意义。既有的研究表明 ,股价在发生涨跌停时存在一定的过度反应。然而 ,本研究发现 ,在股价发生涨跌停时 ,虽然涨跌幅限制不能完全消除过度反应 ,但是可以显著地减小而不是增大过度反应的程度。本研究还发现 ,价格涨跌停本身并不是导致过度反应的原因 ,因为股价不仅在涨跌停时存在过度反应 ,而且在大幅度变化但未达到涨跌停时也存在过度反应。本文据此认为 ,没有证据表明价格涨跌幅限制具有助涨助跌作用。     

证券交易机制影响股价吗?——对中国股票市场的再检验

本文在对分别按照开盘价和收盘价计算的两种收益率的比较中发现了极值聚集现象 ,文中将形成这一现象的原因归结于市场中涨跌幅限制的存在 ,并建立了一个简单模型对此进行了说明。其后 ,利用市场中不存在涨跌幅限制时期的数据对该模型进行了验证。在结论部分 ,本文分析了除交易机制外造成两种收益率差异的其他因素 ,并认为有关交易机制对股价行为影响的研究有待深入。     

Do the Forward Sales of Real Estate Stabilize Spot Prices?

We examine the effect of forward sale (pre-sale) activities on the volatility of spot prices in the real estate market. The abundance of pre-sales data and major changes in regulatory control on the pre-sale market during the 90's in Hong Kong allow us to undertake empirical tests using Hong Kong's real estate data. Our results show that the volatility of spot prices increased significantly after forward sales were severely dampened by regulatory control measures introduced in 1994, but decreased again when the measures were partly relaxed in 1998. The results contribute to the long lasting debate on whether the introduction of a futures market reduces the volatility of spot prices. Previous studies were mainly conducted in markets with low transaction costs, notably financial markets. By utilizing the unique regulatory changes in the pre-sale market of Hong Kong, we are able to conduct an experiment on the conditional volatility of spot prices in a high information-cost environment, thereby shedding light on the important role of forward housing contracts in providing price expectation information for spot trading.