Past research has shown that even though science is commonly viewed as essential for effective policymaking, Democrats and Republicans cite different scientific research when creating policy — even when addressing the same topic.
Now, a new Northwestern study analyzing congressional reports, hearings and think tank publications from around the country, has found that bipartisan citations, while rare, highlight papers of exceptional scientific influence. Policy documents citing these papers also receive more citations, amplifying their policy impact — and perhaps providing a pathway for future bipartisan successes. The study was published in the journal PNAS.
The research team, led by the Kellogg School of Management’s Dashun Wang and Alexander Furnas, observed that bipartisan-cited science is unevenly distributed, concentrated in economics, fiscal policy, regulation and healthcare, but notably absent in climate governance, inequality and race and gender. Wang is the Kellogg Chair of Technology and a professor of management and organizations at Kellogg and of industrial engineering and management sciences at McCormick School of Engineering and Applied Science, director of Kellogg’s Center for Science of Science and Innovation (CSSI), Northwestern Innovation Institute and co-director of Kellogg’s Ryan Institute on Complexity. Furnas is a research assistant professor at Kellogg CSSI.
“Our study offers the first systematic analysis of scientific papers cited in both Republican and Democratic policy documents,” Furnas said. “These results show that bipartisan engagement, though limited, marks a uniquely influential core of science in both research and policy.”
The numbers
Access to large-scale citation data in policy documents is relatively new, according to researchers. Overton Index, a database of policy document citations Furnas and Wang used to source the policy documents, has been the go-to place for researchers looking to measure fundamental questions about where policymakers are looking for evidence.
Researchers looked at congressional committee reports and hearings (1995-2022) from the 104th through 116th Congresses and publications from 121 U.S.-based ideological think tanks that have discernible ideologies as of left or right of center. Congressional committees’ ideology was determined by whether the committee chair is/was a Republican or Democrat. This totaled 424,199 references to 191,244 unique papers.

