Patterns in the use of problem- and solution-oriented evidence in legislative discourse: the case of pesticide policy in Switzerland

Factual knowledge plays a key role in building support for policy change. While change does not depend on factual information alone, it helps in both defining problems and finding solutions. By their very nature, policy issues are controversial and subject to political discourse. Factual knowledge becomes part of this discourse when it is used as evidence to either support or oppose a particular problem definition or solution. In the context of the Swiss parliament’s discourse on pesticide risk reduction between 2013 and 2022, we examined how problem- and solution-oriented evidence were used in both proposing and opposing policy change. To do so, we used computational text classification methods to examine policy documents produced by actors in the parliamentary arena. Our results indicate clear patterns in how evidence was used by these actors. While proponents of change regularly used problem-oriented evidence to highlight the risks of pesticides, opponents relied more on solution-oriented evidence to show that current policies are sufficient and additional policies are unnecessary. Furthermore, over time, those who opposed change shifted from using problem-oriented evidence to using more solution-oriented evidence. We argue that this is related to both triggering events and the advancing accumulation of knowledge about the problem, also known as knowledge creep. Thus, evidence use in political discourse is influenced by several factors, the effects of which may vary in magnitude and overlap over time.