Off the beaten path: what drives scientists' entry into new fields?

Given that venturing into unknown territory carries substantial risk, scientists do not take the decision to enter a new field lightly. This paper analyzes a broad set of factors associated with the risks and rewards from entry into new-to-the-researcher scientific fields, including individual capacities and preferences as well as incentives stemming from career progression and access to funding. Using a panel of researchers in biomedical sciences and science and engineering from a large European research university, we find that productivity affects new field entry as such but is not associated with entry into fields that are very distant to one's current expertise. Scientists in more senior ranks, with larger co-author networks and collaborating with PhD students, are more likely to enter new fields, but these factors do not represent an additional push to enter very remote fields. Such "long jumps" are more likely to be made by above-average talented rather than merely productive researchers. Finally, accounting for its endogeneity, we find that funding does not make new field entry more likely.