Samenvatting

How can the use of policy theories help to improve the development and evaluation of public policy. This question is central to this contribution. In order to answer this question, an overview is made of the development of the concept policy theory and its application in The Netherlands. More specifically, the relation between the rational approach of using policy theories and the quest for evidence-based policy is made. In addition, the possibilities and risks of theory-based evaluation ex post are explored. An important issue in both policy development and policy evaluation is the quality of policy information: which evidence counts? What quality criteria should be in place? On the basis of recent research by the Netherlands Court of Audit, an assessment is made of the actual quality of the ex ante evidence-based nature and the ex post effectiveness of safety policy in The Netherlands. The article presents conclusions and perspectives on how a more theoretical underpinning of policy programmes and a good use of theory-based evaluations may contribute to public policies that are not only effective, but that are also more open to policy-oriented learning.