Solving endogeneity problems in multilevel estimation: an example using education production functions

This paper explores endogeneity problems in multilevel estimation of education production functions. The focus is on level 2 endogeneity which arises from correlations between student characteristics and omitted school variables. Theses correlations are mainly the result of student stratification between schools. From an econometric point of view, the correlations between student and school characteristics imply that the omission of some variables may generate endogeneity bias. Therefore, an estimation approach based on the Mundlak [20 Mundlak, Y. 1978. On the pooling of time series and cross-sectional data. Econometrica, 46: 69–86. [Crossref], [Web of Science ®] , [Google Scholar]] technique is developed in order to tackle bias and to generate consistent estimates. Note that our analysis can be extended to any multilevel-structured data (students nested within schools, employees within firms, firms within regions, etc). The entire analysis is undertaken in a comparative context between three countries: Germany, Finland and the UK. Each one of them represents a particular system. For instance, Finland is known for its extreme comprehensiveness, Germany for early selection and the UK for its liberalism. These countries are used to illustrate the theory and to prove that the level of bias arising from omitted variables varies according to the characteristics of education systems.     

Lost in data translation: A critical review of datasets on refugees

Quantitative data are the backbone of the international refugee regime. Academic researchers and international organizations have been drawing attention to the problems of refugee data that obscure refugee vulnerabilities. Despite these efforts, the limitations of quantitative refugee data, particularly with regard to gendered aspects of refugee vulnerabilities, have often been overlooked. This article aims to address this issue by examining the major limitations of quantitative refugee data. It focuses on the question of “What are the major limitations of quantitative refugee data regarding gendered aspects of refugee vulnerabilities?” By conducting a systematic review of 67 datasets from international organizations, nation-states, and independent data collectors, it argues that there are five fundamental problems with the data: (1) lack of disaggregation, (2) lack of cross-tabulation and inability to harmonize datasets, (3) inconsistent periodization frequency, (4) lack of sex and gender diversity measurement, and (5) survivor bias. This article highlights the importance of critically analysing the data that informs theories and decisions regarding refugee vulnerabilities.     

Automated measurement of infant and mother Duchenne facial expressions in the Face-to-Face/Still-Face

Although still-face effects are well-studied, little is known about the degree to which the Face-to-Face/Still-Face (FFSF) is associated with the production of intense affective displays. Duchenne smiling expresses more intense positive affect than non-Duchenne smiling, while Duchenne cry-faces express more intense negative affect than non-Duchenne cry-faces. Forty 4-month-old infants and their mothers completed the FFSF, and key affect-indexing facial Action Units (AUs) were coded by expert Facial Action Coding System coders for the first 30 s of each FFSF episode. Computer vision software, automated facial affect recognition (AFAR), identified AUs for the entire 2-min episodes. Expert coding and AFAR produced similar infant and mother Duchenne and non-Duchenne FFSF effects, highlighting the convergent validity of automated measurement. Substantive AFAR analyses indicated that both infant Duchenne and non-Duchenne smiling declined from the FF to the SF, but only Duchenne smiling increased from the SF to the RE. In similar fashion, the magnitude of mother Duchenne smiling changes over the FFSF were 2–4 times greater than non-Duchenne smiling changes. Duchenne expressions appear to be a sensitive index of intense infant and mother affective valence that are accessible to automated measurement and may be a target for future FFSF research.     

谈英语学习策略与大学生英语学习成绩的关系

学习策略研究近年来已经成为教育学、心理学领域研究的热点问题.本文通过对参加英语专业四级考试的学生不同的学习策略的分析,以期找到成绩提高学生英语学习的学习策略.     

INDIVIDUAL WELFARE WHEN CONSUMERS CAN SHOP FOR HEALTH INSURANCE

The statewide system of health insurance exchanges established by the Affordable Care Act (ACA) of 2010 will allow millions of U.S. citizens to change their health care policies more easily than they can switch automobile or homeowner insurance coverages, because deniability based on prior claim history is illegal. Focusing on this consumer endogeneity of health insurance policy choice, we examine the individual moral hazard welfare implications of a reduction in the price of medical care, which is a potential consequence of the ACA. We show that endogenous policy choice plays a key role in determining the welfare outcome. While moral hazard welfare improvement is not precluded, a distinctly possible outcome is that the consumer revises his/her choice of insurance policy so as to retain some portion of the reduction in expenditure risk caused by the medical care price decrease. In this event, moral hazard welfare loss is higher than it was before the price decrease, although the increased loss is tempered by the endogenous contract choice effect. This result resuscitates an old conventional wisdom. (JEL I11, I13, I30)     

Informal Learning for Citizenship Building in Shared Struggles for Rights: Cases of Political Solidarity Between Colombian and Spanish Organisations

Dominant discourses and practices in international cooperation have been characterised by depoliticisation and unequal power relationships. However, a number of more transformative experiences of cooperation also exist, where joint work between Northern and Southern social organisations is linked with a more political perspective. These kinds of experiences can be considered processes of informal learning in social action: through shared actions, strategies and frameworks and through interaction between organisations, institutions and the grassroots, informal and multidimensional learning processes occur in the people and organisations engaged. The study approaches four cases of networks that have linked Spanish and Colombian organisations which promote advocacy and social mobilisation for the defence of human rights in Colombia. The results show that people engaged in the cases experience intense learning processes that are relevant for the construction of solidarities and a radical global citizenship, but that these processes are also replete with limitations, tensions and challenges.     

非通用语工程师培养的教学与实践——以北航中法工程师学院为例

中国高等教育国际化引出了高等教育与非通用语国家的合作新模式。通过分析非通用语工程师培养的特点指出,一方面,工程师培养模式下的非通用语教学与中国现有的外语专业教学与第二外语教学都存在差别,另一方面,工程师专业课程非通用语授课也不同于国内理工科专业课程的双语教学。针对非通用语工程师人才培养中存在的问题,以北京航空航天大学中法工程师学院为例,从课程设置、课程融合以及教学组织形式等方面来加强非通用语的工程师培养,旨在为中国非通用语国际教育合作提供新的思路。     

中日两国都市同龄学生体质健康状况的对比研究

通过对中日两国都市同龄学生身体形态指标特征的对比分析,运用数理统计的方法,重点探讨中日两国学生体质状况的特点和存在的差异,并预测我国儿童青少年群体体质发展的未来走向,为进一步贯彻落实《中共中央国务院关于加强青少年体育增强青少年体质的意见》,完善我国学校体育的目标和措施提供参考依据。     

Service at risk in delivery operations

This article examines disruption risks at fulfillment centers and develops risk mitigation strategies based on inventory stocking and delivery decisions. It considers a Fortune 150 firm whose delivery operations are designed to fulfill the orders from contracted business customers within the next day. The firm promises its customers that the probability of late deliveries exceeding a certain threshold will be limited. We coin this requirement as the service-at-risk (SaR) constraint. The firm proactively determines the inventory amount to be kept in each fulfillment center. If a disruption occurs, the firm determines the best way to deliver orders from its operational fulfillment centers and vendors under disruption length and demand uncertainty to minimize additional costs and satisfy the SaR constraint. This article makes four main contributions. First, we find a surprising result that total inventory commitment can decrease with risk aversion when there exists a disruption possibility that impacts two nearby facilities together. Using actual data from the motivating firm, the numerical analysis demonstrates that this phenomenon exists in practice. Second, we define a new metric: The Risk Dispersion Index (RDI), which measures the dispersion in risk exposure across fulfillment centers. It leads to a lower and more balanced risk exposure in the firm's delivery operations. Third, we find that a facility may elect to abandon its own customers to serve the customers of a disrupted facility; this behavior becomes more prominent under risk aversion. Fourth, the introduction of demand uncertainty leads to a smaller inventory commitment for a risk-neutral retailer.     

From bias to coverage: What explains how news organizations treat social movements

Why do newspapers cover social movement actors, and why is this coverage sometimes favorable? Early scholarship saw the news media mainly as a source of data on collective action, and sought to ascertain its biases, but scholarship has increasingly focused directly on why movements gain coverage, especially coverage that can advance their goals. To understand why and how newspapers cover movement actors, we start with the insight that movements rely on the news media for many reasons, but their coverage is largely in the control of news institutions. In this review, we focus on perspectives that specify 3‐way interactions between the characteristics of newspapers, social movement actors, and the social and political contexts, but we begin with how news media institutions are organized. We conclude with suggestions for future research that take advantage of the digital revolution of the last generation.