  Scientists collaborate through intricate networks, which impact the quality
and scope of their research. At the same time, funding and institutional
arrangements, as well as scientific and political cultures, affect the
structure of collaboration networks. Since such arrangements and cultures
differ across regions in the world in systematic ways, we surmise that
collaboration networks and impact should also differ systematically across
regions. To test this, we compare the structure of collaboration networks among
prominent researchers in North America and Europe. We find that prominent
researchers in Europe establish denser collaboration networks, whereas those in
North-America establish more decentralized networks. We also find that the
impact of the publications of prominent researchers in North America is
significantly higher than for those in Europe, both when they collaborate with
other prominent researchers and when they do not. Although Europeans
collaborate with other prominent researchers more often, which increases their
impact, we also find that repeated collaboration among prominent researchers
decreases the synergistic effect of collaborating.
