Specification testing for regression models with dependent data

We examine a consistent test for the correct specification of a regression function with dependent data. The test is based on the supremum of the difference between the parametric and nonparametric estimates of the regression model. Rather surprisingly, the behaviour of the test depends on whether the regressors are deterministic or stochastic. In the former situation, the normalization constants necessary to obtain the limiting Gumbel distribution are data dependent and difficult to estimate, so it may be difficult to obtain valid critical values, whereas, in the latter, the asymptotic distribution may not be even known. Because of that, under very mild regularity conditions, we describe a bootstrap analogue for the test, showing its asymptotic validity and finite sample behaviour in a small Monte-Carlo experiment.     

探究第三产业占比对人力资本积累的影响--基于我国2005年-2011年省级面板数据的实证检验

我国正处于产业结构转型的关键时期,一二产业逐渐向第三产业转移。以往研究大多落脚于人力资本对产业结构的影响,而忽略了由于产业转型带来的对高技术人才的需求推动了人力资本的积累。作者认为,产业结构的优化将有助于人力资本的积累,同时,文化消费、教育投入等因素也会影响到人力资本。本文使用2005-2011年,我国31个省份的面板数据,建立了多元线性回归模型,运用工具变量的方法,以金融发展状况作为第三产业占比的工具变量,进行实证研究。在控制了年份和省份的固定效应后,我们发现第三产业占比对人均人力资本有显著的正向影响,产业结构向第三产业转移有利于人力资本积累。在此基础上,我们提出了若干建议来推动产业结构的优化。     

Individual heterogeneity in the returns to schooling: instrumental variables quantile regression using twins data

Considerable effort has been exercised in estimating mean returns to education while carefully considering biases arising from unmeasured ability and measurement error. Recent work has investigated whether there are variations from the “mean” return to education across the population with mixed results. We use an instrumental variables estimator for quantile regression on a sample of twins to estimate an entire family of returns to education at different quantiles of the conditional distribution of wages while addressing simultaneity and measurement error biases. We test whether there is individual heterogeneity in returns to education and find that: more able individuals obtain more schooling perhaps due to lower marginal costs and/or higher marginal benefits of schooling and that higher ability individuals (those further to the right in the conditional distribution of wages) have higher returns to schooling consistent with a non-trivial interaction between schooling and unobserved abilities in the generation of earnings. The estimated returns are never lower than 9 percent and can be as high as 13 percent at the top of the conditional distribution of wages but they vary significantly only along the lower to middle quantiles. Our findings may have meaningful implications for the design of educational policies.     

中国经济增长的可能性:一种基于修正的索洛模型的估算

索洛模型这一经典的经济增长模型有它无可比拟的优点,但对于考察中国问题来说,也有一些内在缺陷.本文根据中国经济增长的特征事实,对索洛模型做出了一些修正,并据此对中国经济增长的可能性进行了重新估算.     

外出从业经历、农地流转行为与农村劳动力转移——基于CHIP2013数据的实证分析

本文基于2013年中国家庭收入调查数据,采用倾向得分匹配(PSM)法和工具变量解决样本选择偏误和内生性问题,实证分析外出从业经历、农地流转行为对农村劳动力转移的影响;同时,运用中介效应模型研究农地流转行为在外出从业经历与农村劳动力转移之间的作用机制。研究结果表明,外出从业经历和农地流转行为对农村劳动力转移有显著的促进作用,农村劳动力转移的概率分别提高57.7%和5.3%;农地流转行为在外出从业经历与农村劳动力转移之间具有部分中介效应,中介效应占总效应的16.88%;并且三者关系存在区域差异性特征。因而为促进农村劳动力有序转移,应加强农村劳动力职业培训,建立规范的土地流转市场,加强管理与完善制度法规,共同营造公平和谐的农村劳动力外出环境。     

Causality: a Statistical View

Statistical aspects of causality are reviewed in simple form and the impact of recent work discussed. Three distinct notions of causality are set out and implications for densities and for linear dependencies explained. The importance of appreciating the possibility of effect modifiers is stressed, be they intermediate variables, background variables or unobserved confounders. In many contexts the issue of unobserved confounders is salient. The difficulties of interpretation when there are joint effects are discussed and possible modifications of analysis explained. The dangers of uncritical conditioning and marginalization over intermediate response variables are set out and some of the problems of generalizing conclusions to populations and individuals explained. In general terms the importance of search for possibly causal variables is stressed but the need for caution is emphasized.     

Optimal Transfer Pricing Method and Fixed Cost Allocation

Prior empirical research on transfer pricing only reported what firms do but seldom explained why. This study moves the research forward by introducing hypothesis testing.
Atkinson (1987) shows that pricing transfers at variable cost when capacity is in excess. as prescribed by economic theory. would induce the buying unit to overstate expected demand at the capacity planning stage and cause a waste of resources. To test whether the strategic issue affects transfer pricing decisions, the study compares pricing methods for long- term transfer situations. which were provided for at the capacity planning stage, and ad hoc transfers.
As well. while the two-step method of charging full cost -charging variable cost for each unit transferred and separately charging a flat fee each period for capacity on reserve -has many good control qualities, it remained just an academic curiosity: there was no evidence of its wide use among firms. This study finds that the two-step method is as widely in use as the one-step method -charging variable cost plus unit fixed costs for each unit transferred.     

Variable labour supply, specialisation-based external economies, and capital inflow

This paper examines the impact of exogenous capital inflow on prices, production, labour supply, and welfare in the presence of specialisation-based externalities. The paper utilises a simple model of an economy that produces one-final good by means of capital, labour, and a large number of varieties of an intermediate good. The intermediate good is produced by means of capital and labour. The supply of capital is exogenous but the supply of labour is endogenous. The presence of internal economies of scale in the intermediate good industry gives rise to specialisation-based external economies in the production of the final good. Perfect competition prevails in the final good industry whereas the intermediate good industry operates under Chamberlinian monopolistic competition. It is shown that exogenous capital inflow decreases labour supply and increases welfare only if the elasticity of substitution between leisure and the final good is equal to or less than unity. The paper also shows that, if trade opens up between two otherwise similar economies, a capital rich country would be a net importer of varieties of the intermediate good.     

区域一体化有利于减排吗？

将环境污染视作非期望产出,在一个拓展的增长收敛框架下讨论了区域一体化的环境效应及其理论机制。基于2003-2014年长三角城市群和珠三角城市群的数据,构建了一个测度区域一体化的新方法,运用工具变量法和双重差分法估计了跨省城市一体化和省内城市一体化对污染排放强度收敛的影响。实证结果显示:区域一体化显著促进了城市间污染排放强度的收敛并有利于减排,且近年来这种减排效应愈明显。污染排放强度呈现出条件收敛特征,经济增长收敛是污染排放收敛的重要原因。中国应利用好区域一体化促进地区协调发展和减排的双重政策红利,进一步促进区域一体化和同城化,大力发展城市群经济,构建城市间共生互利的发展格局,实现共同减排。