Two–step sequential sampling

Choosing the sample size in advance is a familiar problem: often, additional observations appear to be desirable. The final sample size then becomes a random variable, which has rather serious consequences.
Two such sample extension situations will be considered here. In the first situation, the observed sample variance determines whether or not to double the original sample size. In the second situation, the variances observed in two independent samples are compared; their ratio determines the number of additional observations.     

浅析国际直接投资自由化进程中的中国外资政策

随着全球经济一体化的演进，国际直接投资日趋自由化流动。国际直接投资自由化的兴起在全球经济的增长和国际分工深化的进程中发挥了越来越重要的作用。我国是利用国际直接投资的大国，目前正处于向市场经济转轨的关键时期，经济体制和市场结构还不完善，如何在确保国家经济安全的前提下，推进国际直接投资自由化进程，积极合理地扩大引资规模，应成为人们关注的焦点问题。因此，本文试图探寻国际直接投资自由化的经济机理，总结出国际投资自由化的有效制度安排对现行制度进行调整，以期更好地把握和指导我国改革开放实践及进一步融入国际直接投资自由化进程。     

促进城乡和谐发展的理念与理据

城乡差距过大是构建和谐社会的障碍,必须通过"反哺三农"的方式缩小城乡差距,实现城乡间的社会公平与协调发展.从历史贡献补偿角度而言,国民经济应对工业化初期以"剪刀差"方式吸纳的"三农"资金予以补偿;从社会福利角度来说,国民经济的发展不应牺牲涉农主体的利益,政府应对低工资、低地价、农产品低价格予以利益保障或补偿;从社会公正角度而言,政府应保障处于弱势地位的涉农群体的基本权益;从博弈均衡的角度而言,社会公共财政应承担起农村公共品的供给责任.     

发达国家科技政策中的趋同模式解读及其经验借鉴

发达国家的科技和经济能够始终走在世界前列，与它本身的科技政策有着密切的关系。科技政策的激励和引导作用使发达国家的创新机制稳步形成并发挥着决定性作用。本文通过分析发达国家科技政策中的共同做法．从中找出具有借鉴意义的模式．以促进我国创新型国家战略的实施和建设。     

我国城乡居民收入差别测度指标评析及修正

目前，国内学者采用了多种指标测度我国的城乡居民收入差别状况，但是由于这些指标都存在一些缺陷,因而不能准确地反映实际情况。文章介绍和评析了这些测度指标，并提出了调整的城乡居民人均实际可支配收入比指标，用以修正对我国城乡居民收入差别的测度。     

The Capital Tax and Welfare Effects from Asymmetric Information on Equity Markets

This paper explores the implications of informational asymmetries between domestic and foreign investors for optimal capital tax rates and welfare. It adopts a model in which asymmetric information implies a home bias in equity. The paper finds that asymmetric information may raise capital tax rates by reducing the marginal cost of taxation. Furthermore, it shows that investors may gain from informational asymmetries. Although asymmetric information increases the uncertainty as perceived by investors, it may also increase tax rates and allow for a higher consumption of public goods. This reflects that asymmetric information may reduce the distortionary effects of competition among governments.     

经济增长在险水平、条件波动性与经济增长态势研究

经济增长在险水平（GaR）和条件标准差（CSD）能够有效地度量国家经济风险波动的单向性和双向性。利用动态时窗和条件异方差模型，我们发现我国国家经济风险与经济周期波动密切相关，目前的国家风险状态已经体现出明显的稳定性。利用协整关系检验，我们发现我国国家经济风险与经济增长水平之间存在正相关的长期均衡关系，因此采取积极经济政策的“反周期”干预，所诱发的适度经济波动将有且经济快速稳定增长。     

The survivorship bias, share price effect, and small firm effect in Canadian markets

After controlling for survivorship bias, we examine the relation between average returns, firm size, and price levels for Canadian stocks during the 1975-1994 period. Our findings indicate that there is a significant inverse share price level effect in Canadian markets. When we compare the results of the overall sample with the groups of surviving firms and delisted stocks, the latter group shows strong performance for large-size, high-priced stocks. Evidence that supports an independent size effect is less clear for Canadian stocks. A small size effect exists only among the higher share price denominations, which suggests a confounded size-price effect. Although the delisted group returns are statistically different from those of the survivor and the overall groups, which implies some evidence of survivorship bias, the difference between the survivor group and the overall group is weak at best.     

Another look at long memory in common stock returns

We apply the modified rescaled range test to the return series of 1,952 common stocks. The results indicate that long memory is not a widespread characteristic of these stocks. But logit models of the event of a test rejection reveal that rejections are linked to firms with large risk-adjusted average returns. The maximal moment of a return distribution is also found to influence the event of a rejection, but not in a way suggestive of moment-condition failure. Evidence suggestive of survivorship bias is also uncovered. We conclude that there is some evidence consistent with persistent long memory in the returns of a small proportion of stocks.     

Communicating risk for issues that involve ‘uncertainty bias’: what can the Israeli case of water fluoridation teach us?

Water fluoridation is a controversial issue in public health. Despite the uncertainty regarding its efficacy and safety, health officials continue to communicate it as ‘unequivocally’ safe and effective. Our focus is on how health officials and policy-makers in Israel frame the issue of water fluoridation in terms of certainty while promoting a mandatory fluoridation policy. According to van Asselt and Vos, the uncertainty paradox describes situations in which uncertainty is acknowledged, but the role of science is framed as providing certainty. Our study is an analysis of documents and media articles emphasizing the paradoxical language used by official representatives on the controversial topic of fluoridation. A central contribution of this study is that we coin the term ‘uncertainty bias,’ in which policy-makers do exactly what they accuse laypeople of doing, framing uncertainty in biased terms. We found that in order to establish mandatory regulation, health ministry officials expressed information in an unbalanced format, promoting the topic of fluoridation by framing it in exclusively positive terms. This study does not focus on the practice of water fluoridation per se, and is not intended to decide for or against it, but rather, to explore how the debate regarding it is communicated. Understanding this particular case can shed light on how other controversial topics are transformed into health policy that is characterized in equivocal terms.