Figure 3

Differences in collaboration patterns between prominent researchers in North America and Europe. (A)-(H) Number of prominent researcher (PR) collaborations. We plot the distribution of the logarithm of number collaborations for prominent researchers in North America (red) and Europe (blue). The vertical lines indicate the mean log-number of collaborations for each subset. The significance of the difference between the European and North American means was established by resampling researcher affiliations (one sided test). (I) Aggregated distribution for all fields. The log-number of PR collaborations are normalized by the mean in each field so as to make all fields comparable. (J)-(Q) Fraction of intracontinental collaborators, defined as the fraction of prominent researchers in the same continent with which a prominent researcher collaborates. We plot the distribution of the fraction of intracontinental collaborators in North America (red) and Europe (blue). The vertical lines indicate the mean fraction of intracontinental collaborators for each subset. The significance of the difference between the European and North American means was established by reshuffling researcher affiliations (one sided test). (R) Aggregated distribution for all fields. The fractions of intracontinental collaborations in each field are normalized by the mean of the field so as to make all fields comparable. Stars indicate significant differences (***: 1%, **: 5%, *: 10%, n.s.: not significant)