Covariance breakdowns and connectedness of crude oil futures markets with non-synchronous data

ABSTRACT

This article identifies the breakdowns in the covariance of three benchmark crude oil futures markets (WTI, Brent and Dubai) and investigates the changes of market connectedness across the breakdown periods. As the crude oil futures are traded in different regions, this article eliminates the non-synchronous trading data by employing the Vector Moving Average structure and the Bayesian data augmentation approach, which keeps the integrity of original data without changing its properties. The results show that there are significant breaks in the covariance structure of crude oil futures markets. The breakdown periods are consistent with the periods when the market volatilities are at high level and the returns are volatile. The changes of market connectedness are independent of the covariance states, which supports the globalization hypothesis for the crude oil market. The results also suggest that there is more information flow out of the WTI than to the WTI during the sample period, particularly during the breakdown periods in 2008–2009.     

Testing weak-form market efficiency: Evidence from the Istanbul Stock Exchange

The random-walk version of the efficient market hypothesis is tested for the Istanbul Stock Exchange (ISE) using its composite, industrial, and financial index weekly closing prices. The results obtained from three of the tests indicate that all three series are a random walk, but a nonparametic test provides some evidence against a random walk.     

社会主义市场经济的矛盾和问题

市场经济的主要矛盾是生产与消费的矛盾，它决定商品与货币、供给与需求、总供给与总需求的矛盾。社会主义市场经济的主要矛盾是社会主义制度与市场经济体制的矛盾。当前存在的主要问题是生产相对过剩、消费需求不足，分配不够公平、贫富差距过大，市场秩序混乱、腐败现象严重，资源消耗过度、环境状况恶化，等等。只有正确处理社会主义市场经济的矛盾和问题，处理好公有制和私有制、计划与市场、效率与公平、自力更生与对外开放等各方面的关系，才能促进国民经济又好又快地发展。     

Technical Efficiency Estimates of Scottish Agriculture: A Note

Within the UK there has been a lack of studies of technical efficiency at the Scottish level. This note compares the results obtained using Scottish data with a recent study by Hadley [Journal of Agricultural Economics (2006) Vol. 57, pp. 81–100] for English and Welsh farms. Four major sectors are investigated, namely: (i) cereals, (ii) dairy, (iii) sheep and (iv) beef over the period 1989 to 2004. Some distinct differences in efficiencies, returns to scale and causes of efficiency are found.     

Labour use efficiency in the Indian and Pakistani commercial banks

The Indian and Pakistani banking industry is said to have an excessive use of labour due to the significant market share of government owned banks. Both countries have undertaken a process of regulatory reform to bring about market discipline in the usage of inputs and to increase the labour use efficiency and productivity. The focus of this paper is the estimation of productivity and efficiency of labour use in the banking sectors of the Indian sub-continent. The results show that the efficiency of labour use across the Indian sub-continent is improving over time and that foreign banks are more efficient compared to domestically owned banks in their usage of labour.     

我国入境旅游发展现状、趋势预测及策略分析

通过对1997—2006年我国旅游服务贸易出口国际市场占有率指数、旅游服务贸易竞争优势指数和显示性比较优势指数的比较，可以看出我国旅游服务贸易国际竞争力尚不强。结合1978—2007我国历年入境旅游人次和外汇收入数据，通过建立时间序列模型，可以对未来五年我国入境旅游发展趋势进行预测。建议根据我国入境旅游消费结构特征，采用从宏观上实行差异化引导等策略。     

中国郑州棉花期货市场的国际定价功能研究

本文借助计量经济学的分析方法,对郑州商品交易所、纽约期货交易所期棉价格与国内棉花现货价格这三者的关系进行了研究,并测算了郑州商品交易所与纽约期货交易所在价格发现中的贡献份额。研究结果表明,三者之间存在协整关系,纽约期货市场在国际棉花定价体系中占有主导地位,而导致郑州棉花期货市场国际定价功能弱化的原因则是国内棉花期货市场与现货市场缺乏有机联系。     

How to measure mutual fund performance: economic versus statistical relevance

In the present paper a comprehensive assessment of existing mutual fund performance models is presented. Using a survivor‐bias free database of all US mutual funds, we explore the added value of introducing extra variables such as size, book‐to‐market, momentum and a bond index. In addition to that we evaluate the use of introducing time‐variation in betas and alpha. The search for the most suitable model to measure mutual fund performance will be addressed along two lines. First, we are interested in the statistical significance of adding more factors to the single factor model. Second, we focus on the economic importance of more elaborate model specifications. The added value of the present study lies both in the step‐wise process of identifying relevant factors, and the use of a rich US mutual fund database that was recently released by the Center for Research in Security Prices.     

Estimation of the mean in ranked set sampling with non responses

The estimation of the population mean when ranked set sampling [rss] is used for selecting the sample and non responses [nr] are present, is studied. The nr stratum is sub sampled using simple random sampling with replacement. Two strategies are analyzed. One of them is based on the selection of a sub sample from the nr in each cycle. The other uses sub samples selected among the nr in each rank.  The accuracy of the proposed estimators is characterized by the corresponding expected variances. Simulations and real life data are used for analyzing the behavior of them. Acknowledgements: This paper was developed partially during the visit of the author to Université des Antilles et Gouyane. The author gratefully acknowledges the helpful suggestions of the referees and thanks the support of DAAD for visiting Humboldt University where a version of the paper version was made.     

The “swing of the pendulum” from public to market support for science and technology: Is the U.S. leading the way?

The structure and financing of science and technology activities are undergoing a slow, but profound, change. This change can be briefly characterized as a shift from relying and supporting public science to a stronger emphasis on “market-based” incentives for science and technology. In this paper we analyze this shift in a historical perspective, discussing both the theoretical explanations and the empirical trends of the ongoing change. While we do not claim to provide a comprehensive and exhaustive identification of the causes of this shift, we argue that it is largely driven by the perception of a shift of the U.S. policy towards market-based, rather than publicly supported, incentives for science and technology. This, in turn—given the strong economic performance of the United States over the 1990s—has influenced policies in most OECD countries, especially in Europe.We conclude by analyzing the evolution of research in U.S. higher education and find two major trends: an increasing diversity in the number of institutions of different types other than universities and a steady and continuous public funding of the leading U.S. universities. This has allowed the construction of an infrastructure now used largely by the private sector, but it also noted that the United States has not compromised public support for core areas or in those fields in which there is a clear perception that market incentives are not sufficient for meeting the strategic targets of the U.S. policy. The implication is that there is a considerable policy diversity in the U.S. practice and that all aspects of this diversity should be considered when using the United States as a reference.