Peer effects in medical school

Using data on the universe of students who graduated from US medical schools between 1996 and 1998, we examine whether the abilities and specialty preferences of a medical school class affect a student's academic achievement in medical school and his choice of specialty. We mitigate the selection problem by including school-specific fixed effects, and show that this method yields an upper bound on peer effects for our data. We estimate positive peer effects that disappear when school-specific fixed effects are added to control for the endogeneity of a peer group. We find no evidence that peer effects are stronger for blacks, that peer groups are formed along racial lines, or that students with relatively low ability benefit more from their peers than students with relatively high-ability. However, we do find some evidence that peer groups form along gender lines.     

Regulatory compliance,information disclosure and peer effects: evidence from the Mexican gasoline market

Policy makers and regulators are increasingly interested in the use of information disclosure as a regulatory instrument to improve firms’ behavior. However, little has been done using micro-level data to investigate whether information provision may trigger peer influence among firms that affects their compliance behavior. Using station-level inspection verification data from the Mexican gasoline market, this paper examines whether gas stations react to peers’ performance to adjust their own compliance decisions. The information disclosure policy assigned each inspected gas station with green, yellow, or red colors to indicate the status of compliance, minor violation, and severe violation, respectively. We find strong evidence of peer influence triggered by information spillover. The probability of being in compliance increases as the number of “green” peers increases. We use both municipalities and postal codes as geographic boundaries to define potential peers, and find similar results. Our findings also suggest that the magnitude of peer effects varies across municipalities: the effects appear to be greater in wealthier, more educated communities.     

It's not your peers,and it's not your friends: Some progress toward understanding the educational peer effect mechanism

Using a new administrative panel data set from the University of Maryland, this paper explores conventional peer effects and the effects of socially proximate peers at a large public university where some students are randomly assigned to housing. Results show that there is little evidence of robust residential peer effects on undergraduate performance. The impact of socially proximate peers' characteristics on student achievement is then examined using an instrumental variables technique. Results indicate that social “friends” do not impact performance more than randomized peers. The paper casts doubt on the notion that social tie formation is the route to peer effects, and urges caution in the continued pursuit of peer effects in education without substantial empirical or theoretical innovation.     

Misery loves company: Social regret and social interaction effects in choices under risk and uncertainty

Extensive field evidence shows individuals? decisions in settings involving uncertainty depend on their peers? decisions. One hypothesized cause of peer group effects is social interaction effects: an individual?s utility from an action is enhanced by others taking the same action. We employ a series of controlled laboratory experiments to study the causes of peer effects in choice under uncertainty. We find strong peer group effects in the laboratory. Our design allows us to rule out social learning, social norms, group affiliation, and complementarities as possible causes for the observed peer group effects, leaving social interaction effects as the likely cause. We use a combination of theory and empirical analysis to show that preferences including “social regret” are more consistent with the data than preferences including a taste for conformity. We observe spillover effects, as observing another?s choice of one risky gamble makes all risky gambles more likely to be chosen.     

同群效应与公司研发*——来自中国的证据

本文研究了“同群公司”的研发支出对公司自身研发行为的影响。研究发现，同群公司研发支出越多，公司自身研发支出也越多。进一步研究发现，在公司与同群公司地理距离较近或同群公司分析师覆盖程度较高情况下，同群公司研发支出与公司自身研发支出的正相关关系更强。此外，同群公司研发支出会提高公司自身研发支出与未来业绩的正相关程度。研究表明，公司会学习同群公司的研发决策，进而改变其自身研发决策，呈现显著的研发支出同群效应；且公司信息解读成本较低时，研发支出同群效应更为显著。本文不仅丰富了关于研发支出影响因素的研究，还拓展了对研发溢出效应的研究。本文的研究结论对公司制定研发决策具有重要指导意义。     

Do peers affect childhood obesity outcomes? Peer‐effect analysis in public schools

This study investigates whether obese peers are a contributing factor in childhood body‐weight outcomes. Using an instrumental variables method on exogenously assigned peers (i.e., new peers), we find that the weight of peers within the same grade and school significantly impacts body mass index (BMI) z‐score of an individual student. The size of the peer effect, however, is negligible. We find no evidence of interaction between newly assigned peer groups prior to assignment. Furthermore, the obese peers variable is significant only for those peers with whom a student interacts.     

Sorting,peers, and achievement of Aboriginal students in British Columbia

Abstract We examine the contribution of differences in school environments to the gap in education outcomes between Aboriginal and non‐Aboriginal students. We find both substantial school‐level segregation of Aboriginal and non‐Aboriginal students and a substantial gap in test scores. Conventional achievement gap decompositions attribute roughly half of the grade 7 test score gap to between‐school differences and half to within‐school differences. The segregation of Aboriginal students suggests that peer effects might explain some of these between‐school achievement differences. However, we find that peer effects associated with a greater proportion of Aboriginal peers, if anything, improve value‐added exam outcomes of Aboriginal students.     

Peer effects in computer assisted learning: evidence from a randomized experiment

We conduct a large scale experiment to investigate peer effects in computer assisted learning (CAL). Identification relies on three levels of randomization. We find an average 0.17 standard deviation improvement in math scores among primary school students. This average effect is the same for students treated individually or in pairs, implying that peer effects double the learning benefit from a given equipment. Among paired students, poor performers benefit more from CAL when paired with good performers and vice versa. Average performers benefit equally irrespective of who they are paired with. This suggests that the treatment is dominated by knowledge exchange between peers. We also find that CAL treatment reduces the dispersion in math scores and that the beneficial effects of CAL can be strengthened if weak students are systematically paired with strong students.     

What can be learned about peer effects using college roommates? Evidence from new survey data and students from disadvantaged backgrounds

Previous papers which examine the importance of peer effects using exogenous variation in college roommates have found only very limited evidence that a student's first year grade performance is influenced by the observable academic characteristics of his/her roommate. One possible explanation for this finding is that peer effects do not play a particularly important role in the higher education setting. However, another very plausible explanation for this finding is that peer effects are important in higher education but that these previous empirical efforts have simply not been “looking in the right place” to find the evidence of peer effects in this setting. Thus, while these papers have received considerable attention due to the general difficulty of finding credible exogenous variation in peer quality, they have difficulty answering the most fundamental question related to peer effects in this higher education—whether peer effects play an important role or not. This paper provides depth to the peer effects literature using unique new survey and administrative data.     

Peer effects on risk behaviour: the importance of group identity

This paper investigates whether and to what extent group identity plays a role in peer effects on risk behaviour. We run a laboratory experiment in which different levels of group identity are induced through different matching protocols (random or based on individual painting preferences) and the possibility to interact with group members via an online chat in a group task. Risk behaviour is measured by using the Bomb Risk Elicitation Task and peer influence is introduced by giving subjects feedback regarding group members’ previous decisions. We find that subjects are affected by their peers when taking decisions and that group identity influences the magnitude of peer effects: painting preferences matching significantly reduces the heterogeneity in risk behaviour compared with random matching. On the other hand, introducing a group task has no significant effect on behaviour, possibly because interaction does not always contribute to enhancing group identity. Finally, relative riskiness within the group matters and individuals whose peers are riskier than they are take on average riskier decisions, even when controlling for regression to the mean.     

The role of spillovers in research and development expenditure in Australian industries

Using administrative data from firms in Australia that conduct research and development (R&;D), we examine how R&;D activity of other firms and public institutions affect a firm's own R&;D expenditure. We distinguish between the impact of peers, suppliers and clients. We examine whether geographical proximity and industrial clustering affect R&;D spillovers. Overall, we detect positive effects on R&;D expenditure from spillovers from peers and clients to firms that are nearby; within 25 or 50?km. R&;D expenditure by academia, unlike by government bodies, has a positive influence on a firm's own R&;D expenditure within state boundaries. We fail to find any significant role for industrial clusters in augmenting spillover effects.     

基础教育中的同伴效应估计

对基础教育阶段不良同伴带来的短期和中长期效应的评估已经成为劳动经济学的热点话题.文章根据最新的2014年中国教育追踪调查( China Education Panel Survey, CEPS)微观数据,考察了不良同伴对学生标准化考试成绩的影响.为了克服反射(reflection)和自选择问题带来的估计偏误,文章依据班级上不良学生的比例而非传统文献采用的同伴成绩来刻画学生所处的班级环境,并控制了组群的自然特征.在控制学生个体特征和家庭因素后发现,学生所在班级中存在不良同伴,会对学生自身的学习成绩造成显著的负面影响,这一作用在高年级(初三)表现得尤为明显.班级不良同伴比例提高10%会带来平均成绩下降约2分.分样本的回归显示,男性学生、家庭经济状况不佳的学生和住校生的学习成绩对班级不良同伴的反应更敏感.而学校类型的异质性分析则表明,同伴效应在办学情况较差的学校和乡镇/农村学校表现得更明显.进一步的分位数回归结果表明,不良同伴产生的负面效应对成绩较差的学生影响更大.文章的研究发现有利于丰富学界对教育生产函数的认识,也为今后的教育政策提供有益参考.     

Does peer group size influence social preferences and risk taking?

This paper examines whether the ex post relative payoffs of peers as well as the size of the peer group impact an agent's willingness to take risks. For example, persons in a flood plain may be less likely to purchase flood insurance if their neighbors also refrain from purchasing. We generalize the Fehr‐Schmidt (1999) model to allow the intensity of the social preferences to vary with the size of the peer group. Our experiment tests whether subjects are more or less likely to choose a lottery over a fixed payment when others have been assigned either the same lottery or the fixed payment. Using both between and within subject designs, we find risk‐taking behaviour is not responsive to the risks faced by others regardless of the size of peer group.     

Better peers,better scores? A study of twin junior high school graduates in Taiwan

Using data of twin students graduating from junior high schools between 2002 and 2004 in Taiwan, we estimate the effects of peers on high school joint entrance examination performance. To alleviate the potential endogeneity of peer educational achievement, linear models with twin fixed effect and instrumental variables are estimated. Quantile, quantile with twin fixed effect and quantile with instrument variables regressions are also implemented to determine whether estimated peer effects differ at various locations of the testing scores’ conditional distributions. Positive and statistically significant peer effects are found to exist at the mean and at different quantile levels.     

Peer effects in Austrian schools

This study deals with educational production in Austria and is focused on the impact of schoolmates on students’ academic outcomes. We use PISA 2000 and 2003 data to estimate peer effects for 15 and 16 year old students. School fixed effects are employed to address the potential self-selection of students into schools and peer groups. The estimations show significant positive effects of the peer group on students’ reading achievement, and less so for mathematics. The peer effect in reading is larger for students from less favorable social backgrounds. Furthermore, quantile regressions suggest peer effects in reading to be asymmetric in favor of low-ability students, meaning that students with lower skills benefit more from being exposed to clever peers, whereas those with higher skills do not seem to be affected much.     

Using experimental economics to measure the effects of a natural educational experiment on altruism

Economic research examining how educational intervention programs affect primary and secondary schooling focuses largely on test scores although the interventions can affect many other outcomes. This paper examines how an educational intervention, a voucher program, affected students' altruism. The voucher program used a lottery to allocate scholarships among low-income applicant families with children in K-8th grade. By exploiting the lottery to identify the voucher effects, and using experimental economic methods, we measure the effects of the intervention on children's altruism. We also measure the voucher program's effects on parents' altruism and several academic outcomes including test scores. We find that the educational intervention positively affects students' altruism towards charitable organizations but not towards their peers. We fail to find statistically significant effects of the vouchers on parents' altruism or test scores.     

Social aspirations in European banks: peer-influenced risk behaviour

We test a sample of 3,586 banks from 33 European countries to determine whether performances above or below a social aspiration level (median performance of peer banks) influence banks’ aggregate risk levels. Our results are consistent with the behavioural theory of the firm and prospect theory in that we find that bank performance below a bank’s social aspiration level is followed by increased aggregate risk, i.e. risk-taking behaviour in the subsequent year. Although under-performing banks tend to be risk-takers, large banks and banks with high aggregate risk levels tend to limit the increase in their aggregate risk levels.     

Physical appearance and peer effects in academic performance

A large literature examines the role of peer effects in shaping student academic outcomes. This article adds to that literature by introducing a new kind of peer effect – the effect of classmate physical appearance. We document that college students are assigned higher grades when in a classroom with peers who are rated as very attractive. This effect is strongest for female students and appears to be concentrated among the courses of younger and male instructors.     

Evaluating the magnitude and the stakes of peer effects analysing science and math achievement across OECD

What follows is an exercise aimed at estimating peer effects' impact on science and math test scores of secondary school students surveyed in 1995 by the International Education Agency across OECD countries. It is also to discuss their importance for educational policy, particularly regarding the highly sensitive issue of ability-grouping. Using this unique international database. This study assesses the magnitude of the peer effect relative to more traditional inputs. Referring to education policy stakes, we control for the presence of increasing or decreasing return. This study also checks for cross effects in order to determine whether peer effects matter more to low or high SES pupils, and whether their final impact on achievement is affected by the underlying level of heterogeneity within the group. Using a methodology, which a priori accounts for the clustering of the data within countries and schools/classrooms - i.e. fixed/random effect or hierarchical model - our analysis indicates that peer effects are strong determinants of both math and science achievement relative to individual SES and other school inputs. The presence of increasing of decreasing returns is not obvious. But we find systematic evidence that low-ability pupils are more sensitive to peer group characteristics. By contrast, this study also find that - for a given level of the peer effect - higher heterogeneity comes at a certain cost. In brief, these results provide no systematic evidence regarding grouping policies.     

Personality and cognitive skills in network of friends,for multi-ethnic schools

In a multi-ethnic society, friendship among children might be expected to be overwhelmingly shaped by ethnicity and cultural heritage. Using an original panel data-set of classmate networks in multi-ethnic primary schools near Florence, Italy, ($N=396$ children in 2nd and 5th grade), we show instead that cognitive skills and personality traits matter as much as ethnicity in shaping friendships, thus playing the role of elective affinities. We test whether friends affect a child’s personality more than the other way round: to do this, we estimate peer effects. We only find non-significant effect of peers on math grades and a measure of intelligence (KBIT). For personality traits, peer effects are significant only for Extraversion. These findings are crucial for design of immigration policies: rather than emphasizing differences among ethnic groups, a farsighted policy could try to point these elective affinities among individuals.