Science cited in policy documents: Evidence from the Overton database

To reflect the extent to which science is cited in policy documents, this paper explores the presence of policy document citations for over 18 million Web of Science-indexed publications published between 2010 and 2019. Enabled by the policy document citation data provided by Overton, a searchable index of policy documents worldwide, the results show that there are 3.9% of publications in the dataset cited at least once by policy documents. Policy document citations present a citation delay towards newly published publications and show a stronger predominance to the document types of review and article. Based on the Overton database, publications in the field of Social Sciences and Humanities have the highest relative presence in policy document citations, followed by Life and Earth Sciences and Biomedical and Health Sciences. Our findings shed light not only on the impact of scientific knowledge on the policy-making process, but also on the particular focus of policy documents indexed by Overton on specific research areas.