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 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.
The study, "Bipartisan-Cited Science Is Rare, Unevenly Distributed, and Disproportionately Influential," was published Wednesday (April 22) in the journal PNAS.
"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.
"This allowed us to classify basically every citation," Furnas said. "Was this science cited by someone on the right or left? That's a partisan-cited paper. When one of each cited it, we call that a bipartisan-cited paper."
Researchers were then able to compare the two datasets of partisan-cited versus bipartisan-cited papers. The results were that 6.7% of papers showed bipartisan use in policymaking, and though the bipartisan citation is rare, that science is proven to be extraordinarily impactful in both the science and policymaking world.
"Bipartisan-cited science tends to be among the 5% most highly cited papers published within the field and year," Furnas said. "Nearly 70% of bipartisan-cited papers fall into that category, while only approximately 55% of partisan-cited papers do."
Furnas continued: "The ones that get bipartisan attention are these superstar papers, canonical field-defining kind of things on average," Furnas said. "And that tells me something about what kind of stuff can break through."
Bipartisan-cited science seems to be more common in certain areas, such as economics, but not so common in topics such as gender or race, said researchers.
"The more political a topic, the more partisan the science seems to be," Furnas said. "For example, Democrats and Republicans try to get tax policy right. They have different goals for tax policy, but they cite some of the same economists' work. There's not a lot of overlap on things about identity, race, gender, family, global climate resilience, etc."
Why it's important
Researchers emphasized that science is a way that both everyday people and policymakers alike learn about the state of the world and how to intervene. The finding that Democrats and Republicans rarely use the same science to try to learn those things is a problem, according to Furnas.
"I think it's really important for the quality of governance, of democratic governance, that policymakers be able to work from a shared set of facts," he said. "Different political parties have different goals, that's understood. But ideally, you want them to argue over what that information means, their values, but not the science-based information in front of them."
Furnas continued, concluding that it's important to focus on that small percentage of common ground.
"The percentage is small, but sometimes they do use the same stuff. We need to think about interventions to broaden that shared evidentiary basis," he said. "This research is about what makes that small percentage so distinctive, hopefully future work can find ways to leverage that and increase bipartisan engagement with science."
What's next
Researchers want to continue to explore how policymakers engage with science.
"I'd like to be looking more at how the science itself is employed rather than just what gets cited. I think it's important to dig into those things," Furnas said. "I'd love to see what makes this specific research that is cited by both parties so enticing. How can we get more of that kind of research into the hands of policymakers that both sides can trust? This paper doesn't answer that, but it's a setup for that expansive project. And in some sense, this provides us a baseline against which to measure."
