中国粮食生产潜能分析：一个基于“俱乐部 收敛”的视点

我国的粮食单产存在显著的地区差异,不同地区粮食单产的收敛分析有助于预测粮食生产潜能。对1980年至2012年全国30个省区市稻谷、玉米、小麦三种主粮单产数据的收敛分析发现,传统收敛β收敛与σ收敛的分析结果相互冲突,并且与现实不符。而俱乐部收敛分析发现,稻谷单产全国范围内趋于收敛;玉米单产同样在全国范围内收敛;但小麦单产则不存在总体收敛趋势,而是收敛于三个不同的俱乐部。进一步以“俱乐部”内最高单产为参照测算三种主粮历年的生产潜能,预测结果显示,实际产量与潜在产量的差距在不断缩小;三种主粮在2012年的潜在总产量为6.6万亿吨,仍比实际产量高26%;初步估计,未来10—20年之内,三种主粮的增产潜能会保持在10%以上。     

新工业革命下物联网与产业融合关系研究

在新工业革命的大趋势下,互联网与物联网的发展促生了新的产业融合方式,并加快了产业融合的速度与进程。分析物联网与产业融合的发展现状、二者关系以及物联网对产业融合五种形式的促进作用,并从物联网的感知层、网络层和应用层入手,研究产业融合对物联网发展的推动效果,提出运用物联网促进产业融合发展的对策建议。     

An Empirical Process View of Inverse Regression

A common approach taken in high‐dimensional regression analysis is sliced inverse regression, which separates the range of the response variable into non‐overlapping regions, called ‘slices’. Asymptotic results are usually shown assuming that the slices are fixed, while in practice, estimators are computed with random slices containing the same number of observations. Based on empirical process theory, we present a unified theoretical framework to study these techniques, and revisit popular inverse regression estimators. Furthermore, we introduce a bootstrap methodology that reproduces the laws of Cramér–von Mises test statistics of interest to model dimension, effects of specified covariates and whether or not a sliced inverse regression estimator is appropriate. Finally, we investigate the accuracy of different bootstrap procedures by means of simulations.     

Understanding Estimators of Treatment Effects in Regression Discontinuity Designs

In this paper, we propose two new estimators of treatment effects in regression discontinuity designs. These estimators can aid understanding of the existing estimators such as the local polynomial estimator and the partially linear estimator. The first estimator is the partially polynomial estimator which extends the partially linear estimator by further incorporating derivative differences of the conditional mean of the outcome on the two sides of the discontinuity point. This estimator is related to the local polynomial estimator by a relocalization effect. Unlike the partially linear estimator, this estimator can achieve the optimal rate of convergence even under broader regularity conditions. The second estimator is an instrumental variable estimator in the fuzzy design. This estimator will reduce to the local polynomial estimator if higher order endogeneities are neglected. We study the asymptotic properties of these two estimators and conduct simulation studies to confirm the theoretical analysis.     

理论观照与实践反思:乡村振兴道路背景下产业融合探究

为从全球性现代化的视野观察中国现代化道路,通过在湖北西部（鄂西南、鄂西北）、渝东南、贵州（六盘水、遵义、黔东北等）等地烟草行业综合体建设进行调查,对城乡融合发展中的产业融合进行综合考察和研究。研究认为,中国的乡村振兴从“战略”提升为“道路”,表明中国式“两条腿走路”的三农现代化道路认知正式成形,乡村振兴道路在本质上讲是“农村就地现代化道路”,以农业为基础的农村就地现代化道路的关键是农村产业的融合发展;走乡村振兴道路,必须坚持政府是“主导”、乡村是“主场”、就地现代化是“主道”、产业融合发展是“主业”、内生发展是“主流”、三农工作队伍是“主体”、城乡等值发展是“主向”,再从土地流转关系、政策法规、主导产业培育、共享经济平台建设等方面,培育和推进乡村振兴中的产业融合工程。     

How far merit selection? Social stratification and the labour market1

The question of how societies allocate occupational positions and subsequent rewards has long been of interest to sociologists. According to one influential theory, the needs of modern industrial societies and economies demand that high-level and functionally important occupational positions are allocated according to meritocratic principles. I argue that, ultimately, employers get the final say about which characteristics are rewarded in the labour market. In order to examine which skills and attributes are required by employers for particular occupations I analyse data drawn from a content analysis of c.5000 British newspaper job advertisements. The results show that both merit and non-merit characteristics are requested by employers in job advertisements, even for occupations falling within the higher classes. I also find evidence that employers have similar requirements for similar occupations, cross-cutting class boundaries.     

基于潜类别随机前沿的区域创新效率及其影响因素分析

运用可根据研究对象的潜在属性内生分组的潜类别随机前沿模型,采用1999-2012年中国各省区数据,研究各省区的创新效率及影响因素。结果表明:以人力资本水平和基础设施状况为条件变量,将全国各省区分成两个技术类别,分别有各自的技术前沿和函数形式,A类别中上海市的创新效率最高,B类别中河北省的创新效率最高;平均来看,各类的创新效率均呈上升趋势,贸易开放、产业结构和金融发展对创新效率均有显著的正向作用,同时创新效率在各类内部均存在俱乐部收敛。     

汉代封事的内容及其运作

＂章表奏议,经国之枢机＂。文书形态和运作机制的变迁,是了解中国古代政治制度成长性变革的一个重要切入点。封事是一种直达御前、＂不使人知＂的机密文书,其内容涉及外戚关系、皇帝得失、国家政治和大汉安危等社会政治生活的各个方面。与普通章奏相比,封事的传递、运转过程绕过了尚书台的拆封和审阅处理,直达皇帝,由皇帝亲自批阅,传递过程简单、直接,中间只有少数几个人员和机构参与封事的传递,略去了审阅和处理环节。