投资者结构与期限结构对期货市场效率的影响研究

有效市场假设认为,投资者不能通过任何信息的获取而获得超额收益,即价格能够及时地反映所标资产的相关信息和风险。通过对上海期货市场金融危机前后交易数据的检验,发现其存在显著的长期惯性利润,证明了其不符合有效市场假设和可能存在市场操纵行为。Granger因果检验进一步发现短期的投机行为越多惯性利润越低,长期惯性利润越高投机行为越多。因此上海期货市场有必要通过减少交易成本和提供更多的交易信息去改善市场结构和效率。     

Forecasting stock market volatility and the informational efficiency of the DAX-index options market

Alternative strategies for predicting stock market volatility are examined. In out-of-sample forecasting experiments implied-volatility information, derived from contemporaneously observed option prices or history-based volatility predictors, such as GARCH models, are investigated to determine if they are more appropriate for predicting future return volatility. Employing German DAX-index return data it is found that past returns do not contain useful information beyond the volatility expectations already reflected in option prices. This supports the efficient market hypothesis for the DAX-index options market.     

The effects of trading activity on market volatility

The paper re-examines the question of excessive implied persistence of volatility estimates when GARCH type models are used. Ten actively traded US stocks are considered and as already established in the literature, when volume traded is inserted in the GARCH (1, 1) or (EGARCH 1, 1) models for returns, the estimated persistence is decreased. Since volume is affected also by within-the-day price movements and hence is not weakly exogenous relative to returns, alternative proxies for trading activities are suggested. It is concluded that the difference between the opening price and the closing price of the previous day accounts also for most of the persistence in the autoregressive conditional heteroskedasticity.     

The long-horizon returns behaviour of the Portuguese stock market1

In the last few years several research studies have challenged the traditional weak-form efficiency tests of the stock market. These studies suggested an alternative to the random walk model, containing temporary and permanent components. If stocks follow such a model then the traditional tests, using returns computed for short intervals would be unable to detect them. To investigate the evidence for such models in the Portuguese stock market ten stock indexes were created. This is a pioneer study of the Portuguese stock market, and uses nominal, real and excess returns, computed for longer horizons. Three methodologies were used: variance ratios, ordinary least squares regressions and weighted least squares regressions. The statistical significance of the results was studied using traditional parametric tests as well as non-parametric tests. The evidence is mixed, as the presence of tendencies towards mean aversion and mean reversion were detected. Results also show that the evidence is very sensitive to the methodology used and the signifcance tests performed. These results, however, do not necessarily reject the weak-form market efficiency hypothesis.     

Underlying assets for which options complete the market

This paper shows that investigations on the spanning power of options in spaces of integrable and continuously distributed payoffs can be conducted in the space of Lebesgue integrable claims on [0,1]. It is proved that there are infinite many underlying assets for which options span spaces of integrable claims. It is also shown that options on a single underlyer fail to complete the spaces of continuous contingent claims that are defined over a noncompact state-space.     

The implication of banking competition: Evidence from African countries

This paper examines how bank efficiency and stability are affected by the market power in Africa. Our results show that the higher degree of market power is associated with high level of efficiency and profitability. The banks with more market power operating are able to be in command of the price and hence improve their profit. The market power has a benefit in both stability and risk. Hence, gain in market will increase the stability and reduce the risk for banking system. Our findings do not support the argument that competition should not be based on a “quiet life hypothesis”.     

基于协调的保险市场与资本市场对接模式研究

本文通过比较美、英、日、德四国的对接模式发现,保险市场与资本市场的和谐对接是资金、产品和制度对接三方面的共融体,是金融市场自然演进与风险资本动态规制的最优范式结合。基于此,我国应在经济、金融微观制度基础变迁的基础上适时选择适合我国国情的可操作和可持续的对接模式。     

Round-the-clock market efficiency and home bias: Evidence from the international Japanese government bonds futures markets

This paper examines how information is processed between almost identical international futures markets: London (LIFFE) and Tokyo (TSE) JGB futures. In these markets, variations in open-to-open changes are virtually the same as those of close-to-close changes, suggesting that information is transmitted efficiently across markets with small opening pricing errors. The overall results confirm market efficiency around the clock, yet the intraday U-shaped patterns in volume/volatility of the London JGB futures suggest home bias in international investments, indicating a less global view of trading than expected. Specifically, at the LIFFE open, London investors rush to rebalance portfolios instead of doing so at the TSE close, which is only one hour before the LIFFE opens.     

我国银行业市场势力与行业效率关系的实证研究

本文研究了我国银行业市场势力及其与行业效率之间的关系,分别以我国银行业的成本效率、规模效率和技术效率为因变量,以市场势力、银行规模、资产配置能力、产权结构、创新程度和稳定性为自变量,构建了三个效率影响因素模型,对市场势力与行业成本效率、规模效率和技术效率的关系进行了分析。结果发现,在总体水平上,市场势力与成本效率、技术效率之间存在显著的负影响,对规模效率的影响不显著。     

商业银行绩效、效率与市场结构——基于中国1994～2005年的面板数据

本文应用随机边界方法(SFA)测度了中国16家全国性商业银行的X效率和规模效率,并在此基础上针对其经营绩效与市场结构间关系的几种经验假说进行了检验。统计结果显示,样本期内各商业银行的效率情况总体上均不断改善,其中股份制银行的X效率水平普遍高于国有银行,但在减速递增的过程中差距在不断缩小;另一方面,国有银行在规模经济上具有显著优势,并且2002年以来优势还在进一步扩大;最后,关于银行绩效与市场结构关系的四个主要经验假说在中国银行业市场均不适用,中国商业银行部门的成本控制优势在迅速扩大业务规模的过程中并未有效地转化为盈利能力的提高。