Salient and contested scientific evidence in debates over sustainable transformation: pesticide policymaking in Switzerland

Research indicates that the increased use of scientific evidence is an important lever for transforming policy toward sustainability goals. We explore how actors use scientific evidence in contests over policy transformation in the agri-food sector. Theoretically, we build on prior research on evidence use in policymaking and the 3i´s —ideas, interests, and institutions—that constitute policy regimes. We argue that some pieces of scientific evidence become salient in policy debates but are contested by competing actor coalitions. Salient and contested means that different actors refer to the same scientific evidence to support arguments for and against options of policy transformation. We posit that, in these arguments, evidence use is closely linked to the ideas, interests, and institutions that actor coalitions want to protect or challenge. We assess our arguments through a close examination of a landmark Swiss policy reform between 2019 and 2022 aimed at pesticide risk reduction. Drawing on policy post-exceptionalism literature to operationalize our analytical categories, we analyzed a comprehensive set of content-coded parliamentary and consultation documents derived from the policy process. Our analysis shows that (1) only a few pieces of scientific evidence became salient, (2) actor coalitions linked scientific evidence to different ideas, interests and institutions in line with their policy preferences, and (3) salient scientific evidence in support of transformation becomes contested when it is “too big to ignore”. We conclude that while salient scientific evidence promotes evidence-informed debate, it does not necessarily provide clear and unambiguous direction for policy.