Robustness checks and robustness tests in applied economics

A common exercise in empirical studies is a “robustness check”, where the researcher examines how certain “core” regression coefficient estimates behave when the regression specification is modified by adding or removing regressors. If the coefficients are plausible and robust, this is commonly interpreted as evidence of structural validity. Here, we study when and how one can infer structural validity from coefficient robustness and plausibility. As we show, there are numerous pitfalls, as commonly implemented robustness checks give neither necessary nor sufficient evidence for structural validity. Indeed, if not conducted properly, robustness checks can be completely uninformative or entirely misleading. We discuss how critical and non-critical core variables can be properly specified and how non-core variables for the comparison regression can be chosen to ensure that robustness checks are indeed structurally informative. We provide a straightforward new Hausman (1978) type test of robustness for the critical core coefficients, additional diagnostics that can help explain why robustness test rejection occurs, and a new estimator, the Feasible Optimally combined GLS (FOGLeSs) estimator, that makes relatively efficient use of the robustness check regressions. A new procedure for Matlab, testrob, embodies these methods.     

Evaluating monetary policy under preferences with zero wealth effect: A Bayesian approach

Both real and monetary macro models have parallely exploited the potential for various preferences in accounting for empirical facts. This paper brings the two literatures together by estimating time non-separable preferences with habit formation in consumption that nests several commonly used preferences. In the absence of wealth effects and external habits, these preferences fail to generate observed inflation inertia and output persistence after a monetary policy shock. Furthermore, the data strongly rejects these preferences in favor of preferences with external habits. An alternative solution is to include habit adjusted intermediate wealth effect preferences which are able to simultaneously generate sluggish responses of the variables to a monetary policy shock and fit the data better.     

降低阳极效应系数节能减排研究

文章对发生阳极效应时的损耗和降低阳极效应系数的可行性进行了分析,制定了相应措施保证电解质中氧化铝浓度,从而提高了效应受控率,达到节能减排的目的。     

“啤酒游戏”的系统动力学分析

在简要介绍了“啤酒游戏”、系统动力学及其仿真软件Vensim的基础上,进一步构建了啤酒游戏的因果关系图和系统动力学流图,并在此基础上应用Vensim/DYNAMO构建了“啤酒游戏”的计算机模型,对其进行了仿真。研究了订货延迟时间对物流库存系统情况造成的影响,比较了两种不同的采购策略对“啤酒游戏”的影响,发现订货延迟时间的存在是造成“啤酒游戏”中“牛鞭效应”的内因,商家过分在意当前的库存与缺货情况,急于补存或者降低库存,反而会造成“牛鞭效应”的加剧。结果表明,如果商家适当的延长库存的补货时间,“啤酒游戏”中的“牛鞭效应”会有所改观,这是现代供应链上的物流企业应该借鉴的。     

基础设施对中国经济增长的影响及机制研究——基于扩展的Barro增长模型

基础设施既可以作为特殊的资本存量直接促进经济增长,又可以通过促进投资和劳动力增加(增加生产要素数量)以及提高存量资本和劳动力的边际生产率(提高生产要素效率)间接促进经济增长。本文构建了一个扩展的Barro经济增长模型,并利用中国1992—2016年省级面板数据和中介效应模型对两条机制进行实证检验。结果发现:基础设施对经济增长具有促进作用,但对交通、能源、通信三类基础设施的影响以及在2008年金融危机前后均表现出异质性。直接效应呈动态上升趋势,中介效应则逐渐下降。针对异质性的原因,本文进一步采用非线性模型进行检验。结果表明我国基础设施对经济增长的促进作用主要表现为规模扩张型、数量型或外延型,而不是以质量型和内涵型为主的形式。能源和通信基础设施对经济增长的总效应具有规模效应,交通基础设施的规模效应不显著,但也对经济增长具有持续促进作用。这说明目前我国三类基础设施仍然具有较大投资潜力。其中的关键是要通过基础设施建设提高生产要素效率。     

分税制改革、地方政府干预和金融加速器效应——基于中部地区1995～2008年面板数据的实证分析

运用双向固定效应模型,实证分析了中部地区地方政府对金融发展的干预对金融加速经济发展的效应的影响。研究表明,在经济转型期,中部地区金融业的低水平稳态发展成为阻碍地区经济增长的不利因素。而地方政府因发展经济的强烈动机,适当干预金融发展能弥补地方金融自身发展的不足,促进金融发展推动地区的经济增长。     

Energy efficiency promotion backfires under cap-and-trade

Major climate-cum-energy policies and respective impact projections rest on the widespread belief that increased energy efficiency can be equated with savings in energy use and emissions. This belief is flawed. Due to the rebound effect emissions savings from energy efficiency improvements will be generally less than what is technically feasible, or even be reversed. By means of an analytical general equilibrium model we demonstrate the latter to be true in a case that is both stark and relevant: if electricity generation is subject to a cap-and-trade scheme with partial coverage, increased efficiency of electric devices leads unambiguously to increased carbon emissions. The result implies that a proper distinction between the energy rebound and the carbon rebound is warranted, and that public policy must carefully consider the interactions between energy efficiency promotion and carbon pricing.     

A Common Base Answer to the Question “Which Country Is Most Redistributive?”*

We believe that what most authors have in mind when referring to the “most redistributive country” is a tax and transfer schedule that is most redistributive across all pre-tax and transfer income distributions. In order to measure each country's tax and transfer redistribution according to the same baseline, we suggest using the transplant-and-compare method of Dardanoni and Lambert (2002, Journal of Public Economics 86, 99–122) to establish a common base. The redistributive effects of countries’ tax and transfer schedules are illustrated by employing microdata on eight countries from the Luxembourg Income Study (LIS). Of these eight countries, Finland is found to be the most redistributive country, according to the common base method.     

中部崛起政策对地区产业升级的异质性影响与机制分析--基于PSM-DID方法的一项拟自然实验

国家中部崛起政策实施13年来,相关地区的经济发展和产业结构发生不同程度的变化。为进一步引导发展,需对这一政策的实施效果作整体评估和检验。基于1999-2013年我国201个地级市的面板数据,运用PSM-DID方法,从长期影响角度评估中部崛起政策实施效果。结果表明,以地区技术复杂度度量的产业结构得到了显著的提升。在此基础上考察中国式财政分权模式下政府财政行为波动对政策效果的影响,结果显示政府财政支出波动对地区产业升级会起到负面作用。进一步的机制检验表明,吸引外商直接投资、积极性政府财政政策、突破路径依赖是实现政策效果的中介变量;政策着力点主要在高技术水平的产业上;由于地区异质性的存在,部分省份产业升级并未达到预期效果。因此,制定新一轮崛起战略措施时,要因地制宜,充分考虑地区异质性,走内涵式发展道路。     

来源国形象、消费者偏见与中国品牌跨国营销——中国电子产品在美国的品牌来源国效应检验

来源国效应对一国产品的海外销售产生着重要影响。本文以在美国销售的中国H公司运动手表作为被试商品,在606份有效样本基础上,通过多元线性回归验证了中国品牌电子产品在美国的来源国效应。通过与其他七个国家进行对比,本文发现,虽然中国在美国消费者心目中的产品国家形象较为正面,但相对中国经济地位和产品质量而言,美国消费者对中国电子产品和中国品牌的"来源国偏见"普遍存在,"Made in China"目前仍是中国品牌在美国营销的不利因素。在以往研究的基础上,本文将来源国效应中的产品国家形象划分为整体绩效形象、整体制度形象和产品类属形象,在此基础上检验了多个消费者因素对来源国效应的调节作用,首次检验了消费者网购依赖度对消费者购买倾向的影响,并且发现消费者产品知识负向调节来源国效应,这一结论可以导出明确的管理启示。本文结论进一步深化了来源国效应相关研究,弥补了发展中国家逆向拓展发达国家市场时来源国效应研究的不足。