杜子春音和二郑音的音义匹配

杜子春音和二郑音,无效音切的比例相当高。除读为外,杜子春音和二郑音都不是杜子春和二郑注的,而是陆德明注的。     

Stable matching problems with exchange restrictions

We study variants of classical stable matching problems in which there is an additional requirement for a stable matching, namely that there should not be two participants who would prefer to exchange partners. The problem is motivated by the experience of real-world medical matching schemes that use stable matchings, where cases have arisen in which two participants discovered that each of them would prefer the other’s allocation, a situation that is seen as unfair. Our main result is that the problem of deciding whether an instance of the classical stable marriage problem admits a stable matching, with the additional property that no two men would prefer to exchange partners, is NP-complete. This implies a similar result for more general problems, such as the hospitals/residents problem, the many-to-one extension of stable marriage. Unlike previous NP-hardness results for variants of stable marriage, the proof exploits the powerful algebraic structure underlying the set of all stable matchings. In practical matching schemes, however, applicants’ preference lists are typically of short fixed length, and we describe a linear time algorithm for the problem in the special case where all of the men’s preference lists are of length ≤3.     

On the mean L1-error in the heteroscedastic deconvolution problem with compactly supported noises

We study the heteroscedastic deconvolution problem when random noises have compactly supported densities. In this context, the Fourier transforms of the densities can vanish on the real line. We propose a truncated type of estimator for target density and derive the convergence rate of the mean L¹-error uniformly over a class of target densities. A lower bound for the mean L¹-error is also established. Some simulations will be given to illustrate the performance of the proposed estimator.     

收入风险、金融教育与家庭金融市场参与

运用中国城市居民消费金融调查数据,基于因果推断的分析框架,采用倾向分值匹配法研究了收入风险、金融教育对家庭金融市场参与的影响。研究发现,收入越稳定,家庭开展金融教育的概率越高;金融教育显著提高了家庭的金融市场参与;按收入风险将样本分组后,上述结论依然稳健,且金融教育对不同家庭金融市场参与的影响具有非对称性。在对家庭收入稳定性分类的基础上,有针对性地增加金融教育的供给,提升家庭整体的金融教育水平,有利于提高家庭金融市场参与度,优化家庭金融资产配置,进而改善家庭金融福利。     

The Demand for Labor: An Analysis Using Matched Employer–Employee Data from the German LIAB. Will the High Unskilled Worker Own-Wage Elasticity Please Stand Up?

This paper uses matched employee–employer LIAB data to provide panel estimates of the structure of labor demand in western Germany, 1993–2002, distinguishing between highly skilled, skilled, and unskilled labor and between the manufacturing and service sectors. Reflecting current preoccupations, our demand analysis seeks also to accommodate the impact of technology and trade in addition to wages. The bottom-line interests are to provide elasticities of the demand for unskilled (and other) labor that should assist in short-run policy design and to identify the extent of skill biases or otherwise in trade and technology.

儿童照料与二孩生育意愿 ——来自上海的证据

本文围绕一项针对上海市育龄女性的生育意愿调查,分别使用二分和有序Logit方法分析儿童照顾对上海市育龄女性的二孩生育意愿的影响。研究发现当育龄女性能够从家庭内和社会中获得更多孩子照料的时间支持时,她们有更高的二孩生育意愿,也会伴有更明确的二孩生育规划;双独家庭能够从父辈获得更多的经济、时间上的帮助,因此他们要比单独家庭和双非家庭更愿意再生一个孩子;居住于上海市城区的女性从某种程度上更易获得孩子的照料资源,有更多的优质教育资源可供选择,因此她们的二孩生育意愿高于居住于郊区的女性。此外,本文通过是否采用了避孕措施对二孩生育的意愿程度做了进一步区分,结果发现当第一个孩子主要是由孩子父母承担照料工作的时候,女性存在二孩生育意愿的程度是最低的,祖辈照料对二孩生育意愿程度的积极影响也明显低于社会性照料,此现象在上海市户籍的女性中体现尤为明显。最后为纠正自选择偏差问题,本文使用倾向值匹配方法(PSM)进一步验证了与首孩性别相比,首孩的抚养成本与接受照料情况显然对二孩生育意愿的影响程度更大。因此,本文认为加大公共托育服务的供给、为育龄女性提供高质量的0-3岁婴幼儿社会照料支持是提高二孩生育意愿的最有效政策。     

Teacher shortages, teacher contracts and their effect on education in Africa

Summary.  To enhance primary enrolment rates, many African countries have launched large teacher recruitment programmes in recent years. Given tight budgetary constraints, teachers are no longer employed in civil service positions, but on the basis of (fixed term) contracts typically implying considerably lower salaries and a sharply reduced amount of professional training. We analyse the effect of this change on educational quality in Niger, Togo and Mali, on the basis of very informative data, which are comparable across these countries. We use a variety of estimation techniques, including a non-parametric estimation of quantile treatment effects. Our results demonstrate that contract teachers tend to reduce inequalities in student outcomes. Overall, the effects are positive in Mali, somewhat mixed in Togo and negative in Niger. This ordering is consistent with theoretical expectations related to the manner in which contract teacher programmes were implemented differently in each of the three countries under study.     

Bayesian and likelihood-based inference for the bivariate normal correlation coefficient

The paper develops some objective priors for correlation coefficient of the bivariate normal distribution. The criterion used is the asymptotic matching of coverage probabilities of Bayesian credible intervals with the corresponding frequentist coverage probabilities. The paper uses various matching criteria, namely, quantile matching, highest posterior density matching, and matching via inversion of test statistics. Each matching criterion leads to a different prior for the parameter of interest. We evaluate their performance by comparing credible intervals through simulation studies. In addition, inference through several likelihood-based methods have been discussed.     

设立村级河长提升农村水环境治理绩效了吗?——基于倾向得分匹配(PSM)的反事实估计

农村水环境长期存在"边治理、边衰退"和地方政府监管乏力问题,通过广泛设立村级河长能促进农村水环境治理绩效的提升吗?基于黄河流域4省份实地调查数据,采用倾向得分匹配法(PSM)实证检验村级河长的设立对农村水环境治理绩效的影响及机制,比较不同流域差异、地理区位及村庄规模下的组群差异。实证结果表明:村级河长的设立能够显著提升农村水环境治理绩效,对上游村庄、中小型村庄、近郊村的水环境治理绩效有显著的提升效应,且稳健性检验后结论依然成立。进一步的机制分析发现,村级河长有效治理的深层原因在于村庄内部知识资源、关系资源、动员能力发挥着中介效应,在政府纵向激励问责机制的驱动下村级河长通过资源整合与策略化动员,有效弥补自身治水资源不足的缺陷,避开低绩效陷阱,进而提升河长制在"最后一公里"的政策效应。     

Matching Using Sufficient Dimension Reduction for Causal Inference

ABSTRACT

To estimate causal treatment effects, we propose a new matching approach based on the reduced covariates obtained from sufficient dimension reduction. Compared with the original covariates and the propensity score, which are commonly used for matching in the literature, the reduced covariates are nonparametrically estimable and are effective in imputing the missing potential outcomes, under a mild assumption on the low-dimensional structure of the data. Under the ignorability assumption, the consistency of the proposed approach requires a weaker common support condition. In addition, researchers are allowed to employ different reduced covariates to find matched subjects for different treatment groups. We develop relevant asymptotic results and conduct simulation studies as well as real data analysis to illustrate the usefulness of the proposed approach.