Simulation driven inferences for multiply imputed longitudinal datasets*

In this article, we demonstrate by simulations that rich imputation models for incomplete longitudinal datasets produce more calibrated estimates in terms of reduced bias and higher coverage rates without duly deflating the efficiency. We argue that the use of supplementary variables that are thought to be potential causes or correlates of missingness or outcomes in the imputation process may lead to better inferential results in comparison to simpler imputation models. The liberal use of these variables is recommended as opposed to the conservative strategy.     

The Case of the Missing Pollution Haven Hypothesis

One particularly vexing puzzle for economists and policymakers over the past several decades concerns the empirical significance of the theoretically predicted pollution haven hypothesis. While neoclassical theory and conventional wisdom both surmise that local economies will suffer deleterious effects from stricter environmental regulations, empirical studies have largely failed to validate such claims. This study utilizes the method of matching to show that the impact of stricter regulation is heterogeneous spatially, varying systematically based on location-specific attributes. Previous studies that assume a homogenous response may therefore inadvertently mask the overall impact of more stringent regulations by pooling unaffected and affected regions.JEL Classification: Q25, Q28, H00, L51, R1The authors wish to thank to Michael Crew, Anthony Heyes, an anonymous referee, Werner Antweiler, Randy Becker, Wayne Gray, Shelby Gerking, Michael Greenstone, Vern Henderson, and Arik Levinson. Participants at various university seminars and conferences also lent useful insights to this line of research.     

中医体质辨识结合六味地黄汤治疗老年性阴道炎患者的临床效果

目的探讨中医体质辨识结合六味地黄汤治疗老年性阴道炎患者的临床效果。方法选取2017年6月至2018年6月沈阳市大众医院收治的老年性阴道炎患者104例作为研究对象,随机分为对照组和观察组,每组52例。对照组采用常规治疗方法,观察组在常规治疗基础上采取中医体质辨识结合六味地黄汤的治疗方法。比较两组的治疗效果,以及治疗前后症状体征改善情况、阴道健康状况。结果观察组治疗有效率为96.15%,高于对照组的73.08%,差异有统计学意义(P<0.05)。两组治疗前症状体征积分比较,差异无统计学意义(P>0.05);治疗后,观察组带下量(0.93±0.19)分、白带异味(0.65±0.24)分、阴道灼热(0.63±0.20)分、外阴瘙痒(0.71±0.25)分,低于对照组,差异有统计学意义(P<0.05)。两组治疗前阴道健康积分比较,差异无统计学意义(P>0.05);治疗后,观察组阴道黏膜(1.01±0.38)分、阴道湿润(0.95±0.33)分、阴道弹力(1.32±0.34)分、阴道pH值(0.67±0.36)分、阴道清洁度(0.54±0.25)分,低于对照组,差异有统计学意义(P<0.05)。结论在老年性阴道炎的治疗中,采取中医体质辨识结合六味地黄汤的治疗方法,能够提高治疗有效率,改善症状体征及阴道健康,临床效果显著。     

Nonresponse Bias and Stimulus Effects in the Dutch National Election Study

Bias is a much-debated issue in survey research. Answer effects (respondents claim to have behaved differently than they did in reality), nonresponse bias (nonrespondents differ on important variables from the respondents) and stimulus effects (by participating in a previous wave of a study, respondents change their behavior or attitude) can seriously distort the results of survey research. By using data from the 1998 Dutch National Election Study the authors show that the results of election research can indeed be affected by bias. Not only are significant effects found in the distribution of political attitude and voting behavior variables as a result of both nonresponse bias and stimulus effects, it is also shown that relations between variables change as a result of bias.     

上市公司偏好低现金股利政策的理论思考

上市公司偏好低现金股利政策,损害了中小投资者的利益,加剧了市场投机行为,降低了经营者的风险意识,已成为我国资本市场正常运行与健康发展的一大障碍。本文通过分析我国上市公司偏好低现金股利政策的负面影响和成因,据此提出相关的政策建议。     

上市公司过度融资行为及其治理研究

上市公司过度融资行为,严重损害了债权人和中小股东的利益,扰乱了证券市场的定价和运行秩序,阻碍了我国证券市场的健康发展。本文通过分析我国上市公司过度融资行为的负面影响和经济成因,提出相应的治理措施。     

Heteroscedasticity and Non-Monotonic Efficiency Effects of a Stochastic Frontier Model

We consider a model that provides flexible parameterizations of the exogenous influences on inefficiency. In particular, we demonstrate the model's unique property of accommodating non-monotonic efficiency effect. With this non-monotonicity, production efficiency no longer increases or decreases monotonically with the exogenous influence; instead, the relationship can shifts within the sample. Our empirical example shows that variables can indeed have non-monotonic effects on efficiency. Furthermore, ignoring non-monotonicity is shown to yield an inferior estimation of the model, which sometimes results in opposite predictions concerning the data.     

发展微小企业的宏微观经济效应分析

从宏观层面看,微小企业发展特别突出的功能是向社会提供巨大的就业机会,而且,在经济增长、物价稳定和促进出口方面,微小企业做出了很大的贡献,同时也进一步地深化了财政货币政策效应。从微观层面看,微小企业发展最主要的边际贡献是有助于经济效率的提高,同时,在促进技术和制度创新、分配制度优化、消费结构合理化方面,也有很重要的作用。     

货币政策的产业效应分析——基于中国货币政策的实证研究

本文从基于要素密集度不同的两部门例子出发，说明了由于行业自身的异质性，每个行业对同一货币政策冲击的反应各异。接着利用E—G两步法、ADL模型和基于VAR模型的脉冲响应函数分析1995年后中国六个行业对货币政策冲击的反应。结果显示第一、二产业、房地产业对利率政策冲击反应明显，第三产业、餐饮业和批发贸易零售业反应较小。在此基础上简单分析了造成行业反应不同的原因并给出相关的政策建议。     

Managerial judgment and forecast combination: An experimental study

This paper examines the role of managerial judgment in forming a final forecast, or judging the achievability of a critical level of sales, when multiple forecasts or opinions are available to the decision maker. Several factors that can help improve the quality of human intervention are identified and incorporated in a decision aid. Experimental results show that aided combination can help the decision maker exploit her relevant private information and mitigate the generally observed negative effects of human intervention. Further, the results suggest that emphasizing expected sales, even when the organization is primarily interested in go/no-go decisions, helps improve performance. Several suggestions for future research are presented.

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