劳动力转移对城乡居民收入差距的非线性影响研究

借鉴已有相关研究成果,将劳动力转移、农业技术水平与城乡居民收入差距联系起来思考,可以具体地考察劳动力转移对城乡居民收入差距的影响.文章以农业技术水平作为门槛变量,选取2009—2019年中国31个省份的面板数据,利用泰尔指数测定城乡收入差距,以劳动力转移作为核心解释变量构建面板门槛模型,实证得出劳动力转移对城乡居民收入差距的非线性影响.研究发现:劳动力转移可以缩小城乡居民收入差距,且该影响具有单一门槛效应.在农业技术水平较低时,劳动力转移对城乡居民收入差距收敛效应较小;当农业技术水平越过门槛值达到较高水平后,劳动力转移对缩小城乡居民收入差距的效果几乎增加了一倍.此后,通过替换解释变量泰尔指数为城乡人均可支配收入比、替换核心解释变量农业技术水平为农业生产效率重新建立面板门槛模型,发现上述结论仍然成立,其检验结果具有较强的稳健性.文章将农业技术进步、劳动力转移、城乡居民收入差距这三个重要变量纳入同一模型框架中,在加深劳动力流动影响城乡居民收入差距这一视角的研究的同时,对缩小城乡居民收入差距政策的制定提供了重要的参考意义.     

局部平稳部分线性面板数据模型的统计推断

部分线性模型是一类非常重要的半参数回归模型,由于它既含有参数部分又含有非参数部分,与常规的线性模型相比具有更强的适应性和解释能力。文章研究带有局部平稳协变量的固定效应部分线性面板数据模型的统计推断。首先提出一个两阶段估计方法得到模型中未知参数和非参数函数的估计,并证明估计量的渐近性质,然后运用不变原理构造出非参数函数的一致置信带,最后通过数值模拟研究和实例分析验证了该方法的有效性。     

A Graphical Tool for Interpreting Regression Coefficients of Trinomial Logit Models

Multinomial logit (also termed multi-logit) models permit the analysis of the statistical relation between a categorical response variable and a set of explicative variables (called covariates or regressors). Although multinomial logit is widely used in both the social and economic sciences, the interpretation of regression coefficients may be tricky, as the effect of covariates on the probability distribution of the response variable is nonconstant and difficult to quantify. The ternary plots illustrated in this article aim at facilitating the interpretation of regression coefficients and permit the effect of covariates (either singularly or jointly considered) on the probability distribution of the dependent variable to be quantified. Ternary plots can be drawn both for ordered and for unordered categorical dependent variables, when the number of possible outcomes equals three (trinomial response variable); these plots allow not only to represent the covariate effects over the whole parameter space of the dependent variable but also to compare the covariate effects of any given individual profile. The method is illustrated and discussed through analysis of a dataset concerning the transition of master’s graduates of the University of Trento (Italy) from university to employment.     

半参数空间ZISF的估计、分类与蒙特卡罗模拟

零无效率随机前沿模型（ZISF）包含随机前沿模型和回归模型，两模型各有一定的发生概率，适用于技术无效生产单元和技术有效生产单元同时存在的情形。本文在ZISF的生产函数中引入空间效应和非参函数，并假设回归模型的发生概率为非参函数，构建了半参数空间ZISF。该模型可有效避免忽略空间效应导致的有偏且不一致估计量，也避免了线性模型的拟合不足。本文对非参函数采用B样条逼近，使用极大似然方法和JLMS法分别估计参数和技术效率。蒙特卡罗结果表明：①本文方法的估计精度和分类精度均较高。随着样本容量的增大，精度增加。②忽略空间效应或者非参数效应，估计精度和分类精度降低，文中模型有存在必要性。③忽略发生概率的非参数效应会严重降低估计和分类精度，远大于忽略生产函数的非参数效应的影响。     

Leader negative feedback-seeking and leader effectiveness in leader-subordinate relationships: The paradoxical role of subordinate expertise

From a motivational perspective of feedback-seeking behavior, we examined the mediating role of leaders' negative feedback-seeking from subordinates in the relationship between the quality of leader-member exchange (LMX) and subordinates' evaluation of leader effectiveness, along with the moderating role of subordinate expertise in the mediated relationship. Using 151 unique matched sets of leader and subordinate reports obtained from 5 large Korean companies, we found that the positive relationship between LMX and leader effectiveness was mediated by leaders' negative feedback-seeking. Additionally, the positive relationship between LMX and leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. Lastly, the indirect effect of LMX on leader effectiveness through leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. These findings were obtained after controlling for leaders' power distance and goal orientations that might influence their motives to seek or avoid feedback. Theoretical and practical implications are discussed.     

Language roulette – the effect of random placement on refugees’ labour market integration

Placement of refugees and subsequent labour market integration within a host country represents a key challenge for policymakers and has emerged as one of the most divisive topics in the public debate. Immigration policy in Switzerland adopts random placement of asylum seekers across its different language regions. Hence, this policy allows to estimate the causal effect of language skills on employment chances, as refugees are exogenously placed across regions where the spoken language could either match or deviate from individual language skills. The results of this ‘natural experiment’ indicate substantially higher probabilities of finding employment when asylum seekers are placed in regions with a lingua franca that matches their individual language skills. Additionally, the findings suggest that language course participation can offset the reduced likelihood of employment in cases of a language mismatch. While random placement of refugees may be desirable for political reasons, it is detrimental to the economic integration process. Thereby, the study draws relevant conclusions for a larger European immigration policy.     

“一带一路”沿线国家互联网基础设施的贸易效应——基于贸易成本和全要素生产率的中介效应分析

在"一带一路"建设背景下，研究阐释"一带一路"沿线国家互联网基础设施的贸易效应及其作用机制，对于当前中国优化沿线国家的互联网基础设施建设布局，有效激发贸易效应，应对外贸环境的不利冲击，具有重要的现实意义。文章基于贸易成本和全要素生产率的分析视角，构建2007-2017年中国与45个"一带一路"沿线国家的面板数据，运用中介效应模型实证考察"一带一路"沿线国家互联网基础设施的贸易效应。总体检验结果表明，"一带一路"沿线国家互联网基础设施有利于中国与沿线国家的双边贸易往来，且主要通过降低贸易成本而非提高全要素生产率来发挥贸易效应。异质性检验结果表明，无论区分贸易方向还是沿线国家经济发展差异，互联网基础设施都具有明显的贸易效应，其中：贸易成本的中介效应主要发生在沿线发达国家对中国进、出口贸易中；全要素生产率的中介效应主要发生在沿线国家对中国出口贸易以及沿线发展中国家对中国进出口贸易中。新形势下中国参与"一带一路"沿线国家的互联网基础设施建设，要注意合理布局和把握建设力度，既培育贸易增长新动能，也优化进出口贸易结构。     

陕西省交通基础设施对经济增长的空间溢出效应

为了从外部性角度说明目前陕西省交通基础设施的建设和投资在地域上存在的问题，为陕西省交通基础设施建设方向提供理论帮助，基于陕西省2009~2017年间各市相关数据，在交通基础设施对经济增长效应研究的直接效应和溢出效应基础上，加入空间要素，构建生产函数和空间权重矩阵，通过自相关检验（莫兰指数）、LM检验和 Hausman检验，选取合适的空间面板计量模型对陕西省交通基础设施的经济溢出情况进行研究。研究认为，2009~2017年间陕西省交通基础设施对经济增长的溢出效应（显著）整体为负，但依然存在正溢出的局部地区，即以西安为首的经济聚集区（西安、宝鸡、咸阳）和榆林、延安联合的陕北经济聚集区，资源过于集中和两个高地之间缺乏互联互通是整体呈现负溢出的重要原因。在地域分配的量和质上应充分考虑交通基础设施的溢出效应，避免资源过度集中在西安，在两个经济高地之间打通一条经济要道，并重点扶持相对落后又有发展前景的城市可促使陕西经济发展由总体集聚向总体扩散转变。     

消费者网评使用习惯对网评效应的影响研究---网评奖励效果的中介和调节效应探索*

本文以网购旅游者为调查对象，分析其网评使用习惯及其在网评奖励效果作用下对网络评论效用发挥的影响。通过问卷调查和数据分析发现，网评使用习惯和网评奖励效果都对网评效应具有显著正向影响，但网评使用习惯的影响力大于网评奖励效果。同时，网评奖励效果对网评使用习惯与网评效应间的关系具有显著负向调节效应，它削弱了消费者网评使用习惯对网评效应的影响；但消费者的网评使用习惯不通过网站的网评奖励效果对网评效应发挥作用，网评奖励效果不具有中介作用。可见，在网评使用习惯、网评奖励效果和网评效应三者关系中，网评使用习惯是个独立的影响因素，它并不通过网评奖励效果发挥作用，并且由于网评奖励效果的加入，反而削弱了网评使用习惯对网评效应的影响。研究结论表明，对于网评奖励政策的效果，需要客观辩证地看待，不应一味夸大。     

Heterogeneous treatment effects on Children's cognitive/non-cognitive skills: A reevaluation of an influential early childhood intervention

The 1962–67 High/Scope Perry Preschool Program, a well-known experimental early childhood intervention study that provided quality preschool education to disadvantaged children, has been shown to have had positive impacts on early child development and on a variety of adulthood outcomes. However, most previous analyses have only examined average treatment effects across all program participants without exploring possible effect heterogeneity by children's background characteristics. We investigated this question by first using the 1964–65 Current Population Survey data in combination with the Perry data to construct a scale of child socioeconomic status based on the estimated propensity for inclusion in the Perry program, then analyzing effect heterogeneity within the Perry sample by strata of our socioeconomic scale. We found that the treatment effects of enrollment in the Perry preschool on cognitive and non-cognitive skills were much larger and more persistent among the most disadvantaged children than among others in the Perry program. Furthermore, among the most disadvantaged children, the treatment (i.e., preschool enrollment) affects later outcomes through a reinforcement mechanism of skill development (i.e., early cognitive gain leads to a non-cognitive gain, which in turn leads to later cognitive gain) and a sequential improvement of cognitive skills over time. These findings have important implications for the evaluation of policy interventions in early child development using experimental data.