Partisan Disparities in the Use of Science in Policy

Science, long considered a cornerstone in shaping policy decisions, is increasingly vital in addressing contemporary societal challenges. However, it remains unclear whether science is used differently by policymakers with different partisan commitments. Here we combine large-scale datasets capturing science, policy, and their interactions, to systematically examine the partisan differences in the use of science in policy across both the federal government and ideological think tanks in the United States. We find that the use of science in policy documents has featured a roughly six-fold increase over the last 25 years, highlighting science’s growing relevance in policymaking. However, the pronounced increase masks stark and systematic partisan differences in the amount, content, and character of science used in policy. Democratic-controlled congressional committees and left-leaning think tanks cite substantially more science, and more impactful science, compared to their Republican and right-leaning counterparts. Moreover, the two factions cite substantively different science, with only about 5% of scientific papers being cited by both parties, highlighting a strikingly low degree of bipartisan engagement with scientific literature. We find that the uncovered large partisan disparities are rather universal across time, scientific fields, policy institutions, and issue areas, and are not simply driven by differing policy agendas. Probing potential mechanisms, we field an original survey of over 3,000 political elites and policymakers, finding substantial partisan differences in trust toward scientists and scientific institutions, potentially contributing to the observed disparities in science use. Overall, amidst rising political polarization and science’s increasingly critical role in informing policy, this paper uncovers systematic partisan disparities in the use and trust of science, which may have wide-ranging implications for science and society at large.