27 NOV 2025 (THU) 14:35 - 15:05

Quantifying Knowledge Spillovers from Mobile Scholars

Miss ZHANG Zixuan  

( Supervisor: Prof Frank van der Wouden )

Abstract:

To what extent does knowledge trickle down? In the economic geography and business literature, a general assumption is that novel knowledge can be accessed by others, by hiring persons who have that knowledge. Yet, surprisingly little empirical evidence exists, while it is central to innovation policies and recruitment strategies. We contribute to this gap by quantifying the knowledge spillovers from recruited scholars to other local scholars in the destination cities. 

Using data on 3 million scholars in the OpenAlex database, we can systematically track their career trajectories, their citation behavior, and the geography of their citations between 1975 and 2019. Using advanced matching strategies in combination with staggered differences-in-differences methods, we can estimate the causal effect of mobility on local knowledge spillovers. We do this by comparing pairs of similar scholars for which only the treatment scholar moves to a specific city on the probability of getting cited by scholars from the destination city. Our preliminary findings indicate that when a scholar moves to a new city, the share and the number of citations from scholars in that city to the focal scholar’s work increase by approximately 9% and 24%, respectively. In contrast, similar (control) scholars who did not move to that city do not experience such an increase. This result is indicative of a local knowledge spillover: only the knowledge of the relocating scholar is cited by local peers, not that of a similar but non-local scholar. 

This is the first long-run, systematic empirical evidence on the extent of localized knowledge spillovers from mobile scholars. These results contribute to our understanding of migration, knowledge diffusion and regional economic development. Moreover, the methods developed in this study can be applied to other urban contexts worldwide, as well as to the analysis of other knowledge workers, such as inventors. Finally, university administrators, corporate executives and public policymakers may draw on these insights to inform (regional) innovation policies and recruitment strategies.