Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Using an international data set from the Third International Mathematics and Science Study (TIMSS), we examine academic interactions among classroom peers for each country, and compare them across different countries. To minimize the bias that usually plagues peer effects studies, we take within-student differences between mathematics and science test scores. The results show a significantly positive association between peers' performance and own achievement for most of the TIMSS countries. Moreover, the degree of mutual peer interactions within classroom is found to be surprisingly close across different countries, even if there exists a wide range of institutional differences in middle-school education (e.g. degree of ability mixing).