Experts, Experts Everywhere! Survey Experimental Evidence on How Involving Expertise Affects Decision-Making Legitimacy

Science and expertise are frequently invoked to legitimize policy decisions. However, while prior research suggests broad support for expert-led governance, it often overlooks how citizens differentiate between types of experts and how political beliefs shape these perceptions. This study examines how institutional affiliations of experts—universities, government, and think tanks—influence citizens’ perceptions of legitimacy in political decision-making. Drawing on two pre-registered factorial survey experiments embedded in a survey from Finland (N = 2546), we investigate (1) differences in how actors affect decision-making legitimacy, and (2) how these effects differ depending on the type of issue, outcome favourability and issue salience. Our results show that proposals involving university researchers frequently gain legitimacy, but the exact effects hinge on the type of issue, outcome favourability, and salience. These findings contribute to a more nuanced understanding of how citizens perceive the role of expertise in democratic governance.