Media Briefings

‘Peer Effects’ at School: The Disruptive Impact of Low-Achieving Pupils

  • Published Date: March 2012

Low-achieving pupils seem to have a negative impact on the academic results of their higher-ability classmates by diverting teachers’ attention. That is one of the findings of research by Professor Daniele Paserman and colleagues, published in the March 2012 issue of the Economic Journal.

Their study compares school classes in Israel with different proportions of ‘repeaters’ – pupils who are repeating a year’s education because of previous underachievement. It finds that classes with more repeaters experience a relative deterioration in teachers’ pedagogical practices and in the relationships between teachers and pupils.

A higher proportion of repeaters in a class also increases the level of violence and classroom disruptions – and it has a negative and significant effect on the academic achievements of regular pupils. The negative effect of repeaters is larger on pupils with more disadvantaged socio-economic backgrounds and lower academic achievement.

Every year, parents expend substantial effort, time and resources to ensure that their children will attend a ‘good’ school. But what is meant exactly by a ‘good’ school? There are many dimensions of quality in which schools differ, including the quality of the facilities, the curriculum, the head teacher’s leadership and the teachers.

One important dimension of quality that parents value is also the quality of the other pupils attending the school. Is being surrounded by high ability pupils beneficial? Is being surrounded by low ability pupils harmful? And if so, what are the mechanisms that lead to these ‘peer effects’?

These are the questions investigated in this research. Assessing the impacts of peers’ ability is difficult as pupils self-select into classrooms so that peers’ ability is associated with other attributes that affect pupils’ achievement. In addition, each pupil affects the average outcomes of the classroom and vice-versa, so one needs to isolate the initial impact from the feedback effect.

The authors overcome these challenges by using a measure of peers’ ability that is determined before pupils meet in the classroom and by exploiting variation in the composition of peers’ ability across classrooms that come about by chance. Using data from Israeli middle schools and high schools (ages 12-18), the authors measure the exposure to low-achieving peers by the fraction of pupils in one’s grade that had repeated a grade.

Since grade repetition in Israel is extremely uncommon, the status of being a repeater is determined primarily during elementary school (ages 5-12), usually as early as kindergarten and first grade. This means that repeaters had very little interactions with their classroom peers before they were grouped together in middle school and high school.

Importantly, the variation in the fraction of repeaters in one’s classroom, across different cohorts of pupils attending the same school, can be thought of as random. Some schools have more repeating pupils than others. But whether there happen to be two or three repeaters in this year’s 10th grade as opposed to next year’s 10th grade in the same school is determined largely by chance. This ‘natural experiment’ lends credibility to the causal interpretation of the research findings.

The research first shows that repeaters indeed tend to lag significantly in terms of their academic achievements, even more than other disadvantaged groups of pupils.

Then the study establishes the basic result that the proportion of repeaters in class has a negative and significant effect on the academic achievements of regular middle and high school pupils. The negative effect of repeaters is larger on pupils from a low socio-economic background and who have lower academic achievement.

The study then moves to the exploration of the underlying mechanisms of these peer effects. The analysis shows that there are substantial differences in the way that repeaters and regular pupils assess their teachers and perceive their school environment: relative to regular pupils, repeaters report that teachers are better in the individual treatment of pupils and in the instilment of capacity for individual study. They also report a better relationship with their teachers.

At the same time, a higher proportion of repeaters in the class results in a deterioration in teachers’ pedagogical practices and the relationships between teachers and pupils. It also increases the level of violence and classroom disruptions.

These findings suggest that one of the main channels through which low-achieving pupils negatively affect their peers is by diverting teachers’ attention from regular to struggling pupils.


Notes for editors: ‘Inside the Black of Box of Ability Peer Effects: Evidence from Variation in the Proportion of Low Achievers in the Classroom’ by Victor Lavy, Daniele Paserman and Analia Schlosser is published in the March 2012 issue of the Economic Journal. Victor Lavy is at the University of Warwick. Daniele Paserman is at Boston University. Analía Schlosser is at Tel Aviv University.

For further information: contact Daniele Paserman on +1-617-353-5695 (email:; or Romesh Vaitilingam on +44-7768-661095 (email:

Media Coverage

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