Highlights

• New research from the Max Planck Institute for Demographic Research analyzes global migration of scholars, using bibliometric data. They do a side-by-side comparison of this analysis between Scopus and OpenAlex data.
• Counts of scholars by country are highly correlated between Scopus and OpenAlex.
• Migration events are less correlated between the two, but trends in migration between top pairs of countries are consistent between them. There is higher correlation with Western countries, and OpenAlex has more coverage of non-Western countries.
• OpenAlex is open. Scopus is not. This puts limits on how researchers can perform and share this type of analysis.

A new working paper[1] from researchers at the Max Planck Institute for Demographic Research (MPIDR) uses bibliometric data to study the migration patterns of scholars between countries. Within the field of demography, there is a lack of high-quality data about human migration; so this use of scholarly publication data to infer global-scale migration of scholars is a welcome contribution. They compare the use of two sources of large-scale bibliometric data: “Elsevier’s proprietary Scopus and the openly available OpenAlex.”

The findings of the paper suggest that OpenAlex is a source of open data that shows promise as a replacement for the more established—but more restricted—Scopus data. Overall counts of scholars between countries over time have a high correlation between Scopus and OpenAlex, “with a median correlation close to 1.” The analysis of migration events between the two databases shows less correlation overall, but among the top pairs of countries, “the bilateral flows … are consistent in the two databases.” The authors go on to discuss the reason for the differences, noting that “[this] could signal a large difference in coverage of individual migration trajectories between these two databases and can also stem from the small net migration rates which fluctuate with small differences in measurement rather than population counts which are larger and small changes do not cause them to fluctuate.” In other words, while smaller scale trends may present differently between different data sources due to the nuances and idiosyncrasies of each one, the larger-scale trends are consistent.

The results also suggest that, in some cases, OpenAlex may be an even better resource than Scopus for this analysis. The authors note that the magnitude of migration flows is much larger in OpenAlex compared to Scopus, and that “this could indicate that the higher coverage of publications in OpenAlex might help discover some under-explored scholarly migration corridors worldwide.”

The paper does note some limitations of using OpenAlex as opposed to Scopus for their purposes, specifically, “the quality of the author name disambiguation and identifiers in OpenAlex needs further evaluation in future research.” Evaluating the job that OpenAlex has done assigning authors to all of their papers was outside the scope of this research, but they are able to refer to established research validating the Scopus data. We look forward to this validation on the OpenAlex data both from us and from other independent researchers. We’re also happy to say that we are continually making improvements in our author name disambiguation, so our data will be getting better and better!

Finally, there is the big difference between the two services: OpenAlex is open, while Scopus is not. The authors touch on this several times throughout the paper, both directly and indirectly. They mention that they must limit the years of their analysis, due to “our license terms for Scopus data”. In their Methods section, they describe the multiple steps they had to take to gain access to and acquire the Scopus data, while for OpenAlex, the process was much simpler: “we obtain the publicly available data and process it ourselves”. And in the Acknowledgements section, they explain that the Scopus license terms only permit sharing aggregated results, and no individual data is shared.

Overall, we are very proud that OpenAlex is being recognized as an emerging high-quality, completely open source of bibliometric data that can be used for demographic research. The lack of restrictions on our data is extremely important as it eliminates barriers that researchers face in doing their work. Please check out their paper to learn more about their work!

[1] Akbaritabar, A., Theile, T. & Zagheni, E. Global flows and rates of international migration of scholars. WP-2023-018 https://www.demogr.mpg.de/en/publications_databases_6118/publications_1904/mpidr_working_papers/global_flows_and_rates_of_international_migration_of_scholars_7729 (2023) doi:10.4054/MPIDR-WP-2023-018.