发表偏倚的原因、后果与预防研究

从4个方面对发表偏倚这一现象进行了研究: 1)发表偏倚的定义;2)发表偏倚产生的原因以及作者、编审者、资助者在选择性出版研究结果中所起的作用;3)发表偏倚的后果;4)发表偏倚的多项预防措施.     

Assessing School Readiness: Validity and Bias in Preschool and Kindergarten Teachers' Ratings

As a part of efforts to evaluate and monitor the increasing public investment in early childhood education, teachers are being asked to assess children's school readiness. In this study, preschool teachers and kindergarten teachers rated children's skills in three areas (kindergarten readiness, academic skills, and communication skills), and these ratings were compared with direct assessments of the children's skills. Ratings by both groups of teachers tended to be more highly related to basic skills, such as counting and number naming, than to abilities such as solving applied problems and using expressive and receptive vocabulary. Preschool teachers' ratings had a lower association with children's observed skills and abilities than kindergarten teachers' ratings. Ratings of children attending Head Start were systematically inflated, but this relationship was mediated to a significant extent by the teachers' levels of education. More educated teachers rated children in a manner consistent with the children's directly assessed skills. Implications of these findings for informing future efforts to assess school readiness by using teacher ratings are discussed.     

Gender ratios at top PhD programs in economics

Analyzing university faculty and graduate students data for ten of the top U.S. economics departments between 1987 and 2007, we find persistent differences in the gender compositions of both faculty and graduate students across departments. There is a positive correlation between the share of female faculty and the share of women in the PhD class graduating six years later. Using instrumental variable analysis, we find robust evidence that this relation is causal. These results contribute to our understanding of the persistent under-representation of women in economics, as well as for the persistent segregation of women in the labor force.     

The influence of heterogeneous exposure and pre-deliberation queries on pretrial publicity effects

Prior research on pretrial publicity has produced mixed results and a roughly equal number of studies show an effect, show no effect, or show mixed results. We explored the effects of (a) homogenous vs. heterogeneous exposure (whether deliberating jurors were all exposed to the same publicity or not) and (b) pre-deliberation queries as potential contributors to mixed results. We found an effect for positive but not negative publicity on conviction rates but not evidence ratings. Exposure heterogeneity appears to explain these differences and pre-deliberation queries did appear to play some role in the obtained outcomes. Overall these findings do not replicate a robust publicity effect and future research should consider how homogeneous exposure and pre-deliberation opinion queries influence results.     

Momentum sequence and environmental climate influence levels of perceived psychological momentum within a sport competition

The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot–wet vs. neutral) on supporters’ (i.e. virtual observers’) reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot–wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters’ PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot–wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism.     

Exploring the Effects of Financial Aid on the Gap in Student Dropout Risks by Income Level

Using national survey data and discrete-time logit modeling, this research seeks to understand whether student aid mediates the relationship between parental income and student dropout behavior. Our analysis confirms that there is a gap in dropout rates for low-income students compared with their upper income peers, and suggests that some types of aid are associated with lower risks of dropout. Thus, we examine the interaction between financial aid type and parental income to explore whether, and if so how, different types of aid may reduce the dropout gap by income level group. We find that the receipt of a Pell grant is related to narrowing the dropout gap between students from low- and middle-income groups, although overall the interaction between Pell grant and income is not significant. Loans and work-study aid both have similar effects on student dropout across all income groups. Methodologically, our results demonstrate the need to model dropout behavior temporally and to avoid main-effect bias by incorporating interaction effects.

"三农"难题成因:历史嬗变与现实探源

"三农"问题已成为中央政府与社会各界高度关注的社会焦点,"三农"问题能否顺利解决直接影响到中国农业的可持续发展与社会经济的全面进步。本文从历史检索与现实反思有机结合的视角,系统探讨了中国"三农"难题的四大成因,即:市场之因、制度之因、国情之因与政策之因,从而为"三农"难题的有效化解提供了基本的理论前提。     

注册报告制对科技期刊论文发表的变革性影响分析

学术发表偏差的存在使非阳性科学研究难以获得支持,并且滋生了论文数据造假的现象。注册报告制论文发表模式是一种新型的学术论文发表机制,它不注重于论文的研究结果,而是把重心更多地集中于研究开展的过程。本文分析注册报告制的背景与内涵,阐述注册报告制论文发表的全过程,分析该制度与传统学术论文发表制度的优劣势,并归纳注册报告制近年来的发展趋势,从而提出推动注册报告制在我国发展的建议。