Jesper Dahl Kelstrup, Jonas Videbæk Jørgensen and Magnus Paulsen Hansen
This blog post is based on the Evidence & Policy article, ‘The disenchanted fairy godmother: comparing how and why evidence-based management and public service professionals influenced policy performance in public school and active labour market policy in Denmark’.
Almost two decades ago Carol H. Weiss and co-authors described the idea of evidence-based policies as a ’fairy godmother’ with ’some warts’. In other words, although evidence-based policies clearly entailed some challenges and drawbacks, like discounting local professional judgement, it was still worth pursuing to ’increase the rationality of decision-making’, as they put it.
Yet, studies of evidence-based policy making in action in the past decades have shown that although the aspiration to use evidence to enhance the legitimacy and effectiveness of policies is still widely shared, it often falls short. A common explanation for failure is the presence of various barriers. In our Evidence & Policy article, we critically revisit Weiss and her co-authors’ argument to question whether the challenges related to evidence-based policy making are in fact simply ’warts’ that can be removed, or are more fundamental challenges associated with the aims and management of evidence-based policy making in different policy areas.
The article examines how and why evidence-based policies may fail to improve policy performance. It does so through a comparative analysis of evidence-based policies and management in Danish public school and active labour market policies after 2000. The two cases are characterised by similar policy performance problems but vary in terms of evidence-based management styles and responses from public service professionals.
We find that evidence-based policy making did not resolve performance problems in either case, but for different reasons. Hence, the ’disenchanted fairy godmother’. The case-studies show that it is important to set realistic expectations about the potential of using evidence in resolving policy performance problems. This implies shifting the focus from removing barriers or ‘warts’ associated with the evidence to focusing on developing more realistic – and modest – expectations of the ability of evidence to solve policy performance problems. The intent is to avoid overstating the promises of evidence-based policy making.
The study thus adds two key insights to the literature on evidence-based policy making and management. First, we point to the importance of how policy capacities convert into policy decisions over time. In the case of employment policy, an incremental strategy with gradual, incentive-driven and repetitive policy changes had a better chance of increasing prioritisation of evidence-based means among public service professionals than the large-scale evidence-based reform enacted in the case of public school policy.
Second, our study points to the importance of professional norms in the two policy areas for the legitimacy of evidence-based policy making. Reactions to adverse effects of evidence-based management become more significant when policies are confronted by strong professional norms and when collective organisations are in place to react to them by engaging in policy conflict. The failure of a public school reform introduced in 2014 to achieve its objectives was so profound that it led the Ministry of Education to return to a collaborative approach. In employment policy, a similar process may be happening as job centres are in the process of being reformed and dismantled. The importance of the power of public service professionals for policy implementation is not new. Yet, to sustain the legitimacy of evidence-based policies over time, expected responses from public service professionals should feature more prominently in ministerial strategies for evidence-based management, including in central assessments of the costs and benefits of implementing evidence-based policies.
Image credit: iStock.
Jesper Dahl Kelstrup, Associate Professor of European Public Policy, Roskilde University, Denmark. Jesper’s research focuses on knowledge politics and utilizations in public policies and administrations.
Jonas Videbæk Jørgensen, PhD, Roskilde University, Denmark. Jonas’ research focuses on government ministries and the use of evidence in education and employment policy.
Magnus Paulsen Hansen, Associate Professor, Roskilde University, Denmark. Magnus’ research focuses on the politics and sociology of unemployment and the turn towards active labour market policies and workfare across the OECD countries.
Read the original research in Evidence & Policy:
Kelstrup, J.D. Jørgensen, J.V. & Hansen, M.P. (2025). The disenchanted fairy godmother: comparing how and why evidence-based management and public service professionals influenced policy performance in public school and active labour market policy in Denmark. Evidence & Policy, 10.1332/17442648Y2025D000000044.
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