Diversification, integration, and openi...

Closely-associated with calls for evidence-based policy-making, computer models are increasingly used to support public policies on a wide range of complex and controversial issues, ranging from energy and trade policies to regulating chemicals. In this article, we discuss three trends in modelling for policy and their implications for the authority of models in policy-making. First, we observe the proliferation of models and the differentiation of respective modelling landscapes and communities, resulting in intensified competition for political authority and early path dependencies in their political use. Second, different models are increasingly coupled or integrated into complex model frameworks, raising questions of comprehensibility and accountability. Third, modelling for policy experiences calls for transparency and opening that should serve scientific demands of replicability and verifications as well as political demands of legitimacy. In conclusion, we emphasise the continuous relevance of social scientific analyses of modelling for policy.