A play-the-winner-type urn design with reduced variability

We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.     

正交实验设计方法在B to B电子商务体系质量改进中的应用

电子商务在全球快速地发展，中国企业面临着由B to C方式向B to B方式的转变，本文采用正交实验设计的方法来解决已建成电子商务体系的质量，以满足新的需求。     

The government revenue and government expenditure nexus: empirical evidence from nine Asian countries

The nexus between government revenue and government expenditure has been an important topic in public economics. In this paper, we investigate evidence for cointegration and causality between government revenue and government expenditure for nine Asian countries. We use the recently developed bounds testing approach to cointegration and the conventional F-test to examine Granger causality. Our empirical results suggest that for three out of the nine countries government revenue and government expenditure are cointegrated. Our results on the direction of causation are mixed: (a) for Indonesia, Singapore, Sri Lanka in the short-run and for Nepal in both the short- and long-run we find support for the tax-and-spend hypothesis; (b) Indonesia and Sri Lanka are in conformity with the spend-and-tax hypothesis in the long-run; and (c) for other countries there is evidence of neutrality.     

入世以来两岸经贸关系发展中的问题及其影响

入世6年来,两岸经贸快速发展,但台湾在祖国大陆贸易和利用外资中的地位不断下降。两岸经贸关系至今仍未实现正常化,这对两岸经济发展均带来不利的影响。     

西汉初期“与民休息”政策述论

西汉初期是我国农业经济迅速恢复并达到空前繁荣的时期,这与西汉初期统治集团采取了比较符合实际的"与民休息"的经济政策紧密相关。其时代背景主要是鉴于秦朝实行严刑峻法、横征暴敛政策而亡的历史教训,以及汉初经济崩溃、民生凋敝的实际状况。"与民休息"政策内容丰富,主要包括调整土地关系、赋予军功贵族免役特权、免部分官私奴婢为庶人、减免田税口算徭戍、崇尚节俭和轻刑慎罚等六个方面。"与民休息"的经济政策,将为我们今天解决"三农"问题,发展农业经济,建设社会主义新农村提供有益的借鉴。     

票据无权代理追认制度微探

票据行为是一种法律行为，自然也可以以代理方式为之。民法上有关代理制度的规则一般也都可以适用于票据代理行为。但由于民法与商事法的立法旨趣各有侧重，为促进票据流通、保障交易安全，票据代理不能照搬民法上关于代理制度的规定。票据的无权代理是票据代理中一个非常典型的问题，与民法上的无权代理区别很大，其中存在的问题很多。对于票据的无权代理中是否应当赋予本人以追认权，多数大陆法系国家的立法例与英美法系国家之立法例有所不同。     

Are the Best Small Companies the Best Investments?

Previous research finds that large companies previously judged to be excellent growth companies have subsequently been poor investments. We examine small companies selected by Business Week on the basis of multiple criteria used in annual articles featuring highly rated growth companies. We study the investment performance over the three years before eleven annual Business Week publications and the three years after publication. We find positive excess returns in the pre‐publication period, but negative excess returns in the post‐publication period. This reversal in investment performance appears to be due to a mean‐reversion tendency in operating performance, in which the earnings and the past rates of return on capital of such companies subsequently decrease significantly.     

A note on the existence of unique equivalent martingale measures in a Markovian setting

Simple sufficient conditions for the existence of a unique equivalent martingale measure are provided. Furthermore, these conditions give us a handle on situations where an equivalent martingale measure cannot exist. The existence of a unique equivalent martingale measure is of relevance to problems in mathematical finance. Two examples of models for which the question of existence was unresolved are studied. By means of our results existence of a unique equivalent measure up to an explosion time is proved.     

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.