Multiple pairwise comparison procedures based on the Lin and Wang test for right censored survival data

When comparing the prognosis of more than two groups in clinical trials, researchers may use multiple comparison procedures to determine which treatments actually differ from one another. Methods of controlling the Family Wise Error (FWE) rate for multiple comparisons of survival curves have received attention in the statistical literature. Adjustments such as Bonferroni, Holm's, Steele's and the closed procedure based on the logrank test have been studied. If hazards cross, the adjustments based on the logrank test may not be the most appropriate. Chi (2005) developed multiple testing procedures based on weighted Kaplan–Meier statistics as these statistics may perform better than the logrank for non‐proportional hazards alternatives. The aim of this research is to propose multiple testing procedures based on the Lin and Wang (2004) statistic for all pairwise comparisons. Simulation studies have shown this statistic can be more powerful than the logrank for certain crossing hazards. Through simulation, the FWE rate and power of the Bonferroni and Holm's adjustments based on the Lin and Wang statistic will be studied. For comparison purposes, the same adjustment procedures based on the logrank and Wilcoxon will be included in the simulations. These methods are applied to data from the Bone marrow transplant registry.     

Efficient Estimation and Testing of Alternative Models of Currency Futures Contracts

An efficient systems approach is used to estimate and test two alternative models regarding the pricing of Australian dollar futures contracts traded on the International Monetary Market of the Chicago Mercantile Exchange. Cointegrating relationships among the Australian dollar spot and futures prices, and the US and Australian risk-free rates of interest, suggest alternative error-correction representations for the cost-of-carry model which, with appropriate zero restrictions, yields the unbiased expectations hypothesis. A structural break in the futures price series permits estimation of appropriate models for the full sample in the presence of the break, for the full sample without explicitly modelling the break, and for two separate sub-samples created by the structural break. The restricted and unrestricted cost-of-carry formulations are estimated for all sample sets, the models obtained are found to be statistically adequate, and the qualitative results are reasonably robust across different sample sets for both models. On the basis of the tests of zero restrictions, the cost-of-carry model is found to be empirically superior to the unbiased expectations hypothesis for the four sample sets considered, regardless of the number of cointegrating relations.     

Trading Behavior and Asset Returns: Evidence from the Interday Serial Correlations of Intraday‐to‐Intraday Daily Returns of Taiwan

This paper sheds light on the importance of trading behavior in the determination of asset prices by examining the interday serial correlations of intraday‐to‐intraday daily returns of the Taiwan Stock Exchange (TSEC). The TSEC exhibits positive serial correlation in the beginning and the end of the week and negative serial correlation in the middle of the week. The interday serial correlation is not a result of non‐synchronous trading, bid‐ask bounce in transaction price, or price limits. The serial correlation is positively related to trading volume and similar to the pattern in the US. We suggest that trading behavior seems to be an important determinant of asset prices.     

Jobs-housing balance in an era of population decentralization: An analytical framework and a case study

Despite the well-established theoretical understanding on the benefits of compact cities to the attainment of sustainable transport goals, there has been a worldwide trend of population decentralization in cities. In this paper, an analytical framework, which can be applied to other cities to quantify the potential commuting travel savings and environmental benefits of different job policies in cities having different rates and patterns of population decentralization, is presented. A case study of Hong Kong in the 1992-2002 decade is used to illustrate the analytical framework. The findings suggest that a city’s population patterns did have significant implications on the commuting travel savings from alternative job relocation policies. With a dispersed population pattern, the expected environmental benefits from a job decentralization policy can be very substantial.     

NOTE ON THE PRODUCTIVITY CONVERGENCE OF AIRPORTS IN CHINA

The present paper uses a Malmquist index measure of productivity growth to study the productivity convergence of 25 airports in China during the period 1995–2004. By decomposing the Malmquist index, we find evidence for the convergence of the efficiency level of airports, but not the productivity and technology levels. These results imply that the more productive airports are pushing the frontiers of technology faster by adopting new technology, and that the relative efficiency level of the laggards increases quickly and catches up with the efficiency level of the leaders over time.     

资本主义最能促进自由吗？

本文尝试分析及批评放任自由主义的“自由论旨”,即声称自由是社会的最高价值,以及“小政府大市场”的资本主义制度乃最有效促进自由的观点。作者指出,无论从效益主义或私有产权的立场,都不能支持自由论旨。更重要的是,私有产权的概念本身便涵蕴了自由和不自由两面,而市场竞争导致的经济不平等,其实会大大限制穷人的自由。作者最后指出,无论是透过对自由和自由的条件的区分,还是采用“权利式的自由观”,均难以为资本主义保障了平等的经济自由的说法作出辩护。     

Measuring the productivity changes of Chinese airlines: The impact of the entries of non-state-owned carriers

The competitive environment of the Chinese airline industry has experienced rapid change since non-state-owned airlines entered the market in 2004. We focus on measuring the productivity changes in the Chinese airlines, especially state-owned ones after this change. The results show that non-state-owned airlines are performing better than state-owned airlines. The productivity changes of state-owned airlines are mainly driven by technical changes before or after the entries of non-state-owned airlines. They have little efficiency improvement. However, the productivity changes of private airlines are mainly due to efficiency improvement. The changes associated with international joint venture cargo carrier are due to its significant improvement in both the efficiency and technical changes.     

Corporate Sustainable Development: Testing a New Scale Based on the Mainland Chinese Context

According to the predominant corporate sustainable development (CSD) framework, this exploratory paper verifies that CSD construct can be modeled by integrating the dimensions of social, economic, and environmental development. We first developed and validated measurement scales for these three dimensions based on a survey of 314 managers in mainland China. Then, using structural equation modelling, we confirmed that the proposed model is valid. Therefore, our findings may allow researchers to explore CSD further, and practitioners to develop their understanding of CSD initiatives in organizations.     

Efficiencies and scope economies of Chinese airports in moving passengers and cargo

The paper looks at the technical efficiency of Chinese airports using multi-output stochastic input distance function analysis. This method provides a statistical test of scope economies to investigate the contribution of air cargo transport to airport efficiency. Our findings confirm the presence of scope economies in air passenger and air cargo transport among airports in China. We compare and contrast these results with results obtained from single-output stochastic production frontier analysis in which the effect of scope economies is not included. Our results indicate that the presence of scope economies significantly affects the estimation of technical efficiency, thus implying different efficiency rankings among airports in China.