Missing item imputation for quality-of-life instruments with application to asthma quality-of-life questionnaires

There has been increasing use of quality-of-life (QoL) instruments in drug development. Missing item values often occur in QoL data. A common approach to solve this problem is to impute the missing values before scoring. Several imputation procedures, such as imputing with the most correlated item and imputing with a row/column model or an item response model, have been proposed. We examine these procedures using data from two clinical trials, in which the original asthma quality-of-life questionnaire (AQLQ) and the miniAQLQ were used. We propose two modifications to existing procedures: truncating the imputed values to eliminate outliers and using the proportional odds model as the item response model for imputation. We also propose a novel imputation method based on a semi-parametric beta regression so that the imputed value is always in the correct range and illustrate how this approach can easily be implemented in commonly used statistical software. To compare these approaches, we deleted 5% of item values in the data according to three different missingness mechanisms, imputed them using these approaches and compared the imputed values with the true values. Our comparison showed that the row/column-model-based imputation with truncation generally performed better, whereas our new approach had better performance under a number scenarios.     

Transfer Pricing in Transition Economies: Evidence from Ukraine

Faced with possibilities and challenges of doing business under different regulatory regimes, transnational corporations have developed a number of transfer mechanisms to take advantage of profit maximization opportunities. Transfer pricing is a transfer mechanism widely used by transnational corporations. Implications of transfer pricing for profitability and the need for transfer pricing regulation are well understood by national governments, which is reflected in the fact that more than 60 governments have introduced some form of transfer pricing controls. Transfer pricing is a challenging issue for transition economies as their transfer pricing regulatory systems are less mature than those of developed countries. The authors have initiated an empirical study on transfer pricing strategies in the Ukrainian market. In addition, the national regulatory regime for transfer pricing was evaluated compared to international best practices. This article is an attempt to draw attention of the research community and Ukrainian policy-makers to transfer pricing issues in Ukraine.      

Reciprocal relationships in tax compliance decisions

Reciprocity considerations are important to the tax compliance problem as they may explain the global dynamics of tax evasion, beyond individual tax evasion decisions, toward a downward or upward spiral. To provide evidence on reciprocity in tax compliance decisions, we have conducted a laboratory experiment in which we introduced two types of inequities. The first type of inequity is called vertical, because it refers to inequities introduced by the government when it sets different fiscal parameters for identical taxpayers, while the second type of inequity is called horizontal because it refers to the fact that taxpayers may differ in tax compliance decisions. In this setting, taxpayers may react to a disadvantageous or advantageous inequity through negative or positive reciprocal behaviors, respectively. Our results support the existence of negative and positive reciprocity in both vertical and horizontal cases. When both inequities come into play and may induce reciprocal behaviors in opposite directions, the horizontal always dominates the vertical.     

WTO框架下科学不确定性问题研究

WTO作为多边体制的支柱,不仅规定了货物、服务贸易,而且包括了动植物检验检疫、环境保护等涉及科学技术的领域,但WTO对这些领域的规定含混不清,导致各国对规则的解释往往采用了非统一的科学技术界定标准,这种技术标准成为贸易保护的正当性借口,在实践中许多国家以WTO之名行贸易保护之实。从某种意义上说,全球化肇始的标志是WTO体系,全球化的进一步发展则有赖于对WTO规则的进一步诠释,在环境保护、动植物检验检疫领域采取统一科学证据要件判定体系就成为了支撑WTO自由贸易精神的一个重要制度保障。     

中国房地产税制:存在问题与改革设想

在现代市场经济条件下,房地产税制具有十分重要的功能。现阶段中国房地产税制存在房地产税收功能分散,房地产税种设置交叉重叠现象突出,计税依据不符合国际惯例,房地产保有环节税负偏轻和房地产税权分布结构不合理等问题。中国房地产税制改革已进入基础性制度建设阶段,必须按照"宽税基、简税种、低税率"的原则,实现房地产开发流转环节税收为主向房地产保有环节税收为主的房地产税制转型,去土地财政化,这就要适时开征房产税。开征房产税可以分两步走,近期对居民新购商品房超免税标准部分征收房产税,中长期覆盖到居民已购存量房地产。     

用经济指标规范工程项目管理的探讨

目前工程项目管理存在的问题是项目预期性差,工程质量与经济效益难以协调,其根本的原因是运用经济手段管理项目的力度不够,造成工程的高投入与低产出;在管理方式上,行政命令过多,而经济杆杠发挥的作用不多。为了解决这些问题,必须运用经济的指标去管理与控制项目的运行。     

对《合同法》第402条的再解读

从实体法角度来看,《合同法》第402条在法律适用上的漏洞,应以目的性扩张的方法完成漏洞之补充。其次,在仲裁程序中漏洞补充的实现也会遇到的一定的程序性障碍,应通过对仲裁规则的修改,达到解决这一问题的目的。     

城市居民旅游环境影响与社会文化影响感知问卷量表的开发

城市居民旅游感知研究,对了解和掌握当地居民对旅游发展的态度与行为意义重大,是旅游地可持续发展的必然要求。作者针对国内城市居民旅游感知进行量表开发,先查阅了大量的国内外相关学术文献,接着进行了深入的文献研究,在此基础上设计了调查问卷初稿,问卷初稿包括居民旅游经济影响感知、旅游环境影响感知、旅游社会文化影响感知、旅游发展态度和满意的总体感知、居民参与旅游发展经营管理水平感知等五个维度,每个维度包括正面影响、负面影响两个构面。随后对初试问卷进行小样本调查,根据小样本调查的数据,使用统计分析软件SPSS16.0进行数据分析,对问卷量表进行信度和效度检验,对问卷测量题项进行净化,剔除相关度较低的测量项目,最终形成正式问卷。分析结果证明,量表具有很高的信度和效度。因篇幅所限,文章只对旅游环境影响感知、旅游社会文化影响感知二个维度的净化过程进行论述。     

建设工程项目筹资结构优化

工程项目建设 ,必须要有足够的资金支持 ,面对庞大的资金需求 ,可以从资本市场上寻求投资资金 ,因而如何使筹资结构优化便成为一个重要问题。从筹资方式选择入手 ,分析几种常见筹资手段的特点 ,从中寻求最优筹资结构组合 ,力求避免目前筹资结构单一 ,筹资决策盲目性等问题     

Some efficient random imputation methods

Imputation methods that assign a selection of respondents’ values for missing i tern nonresponses give rise to an addd,tional source of sampling variation, which we term imputation varLance , We examine the effect of imputation variance on the precision of the mean, and propose four procedures for sampling the rEespondents that reduce this additional variance. Two of the procedures employ improved sample designs through selection of respc,ndents by sampling without replacement and by stratified sampl;lng. The other two increase the sample base by the use of multiple imputations.