Evidence-based policy, while an ideal, often faces challenges in achieving its goals due to policy conflicts and implementation hurdles. While some research highlights the need for low conflict, ample evidence, and robust policy capacity, others emphasize the crucial role of practical knowledge and professional expertise. This article bridges this gap by systematically examining the varying roles of practical knowledge in evidence-based policy. The central research question is: How can we understand the role of practical knowledge in evidence-based welfare policies? The article employs two Danish welfare policy cases (active labor market policy and public school policy) from 2010 to 2022 to explore this question. Data sources include ministerial and public documents and interviews with 17 key policy actors (ministry officials, researchers, and stakeholders). The analysis aims to develop a three-stage model that reveals how the interaction between political commitments to evidence, managerial efforts focused on evidence-based policies, and the dynamic role of practical knowledge shapes evidence-based welfare reform. This model contributes to existing literature by illustrating how the interplay of political, scientific-administrative, and practical knowledge shifts across different stages of evidence-based policy development.

Existing literature on evidence-based policy often treats political commitment, policy capacity, and practical knowledge in isolation. While studies acknowledge the importance of political commitment to evidence use, the policy capacity of public administrations to gather and interpret evidence, and the practical knowledge of public professionals, they rarely analyze their interaction. This article addresses this gap by examining how these forms of knowledge interact within a specific policy context. It draws on existing theoretical frameworks that define political knowledge as the know-how and judgment of political actors, scientific-administrative knowledge as systematically analyzed evidence processed by public administrations, and practical knowledge as the 'practical wisdom' of professionals in their communities of practice. The review also examines existing literature on evidence-based management, which attempts to improve policy performance through the adoption of ‘best practices’ derived from evidence, and the potential conflicts that can arise between evidence and the practical knowledge of professionals.

This study utilizes a mixed-methods approach, combining document analysis and semi-structured interviews to explore the role of practical knowledge in evidence-based welfare policies in Denmark. The cases selected for analysis are active labor market policy and public school policy, chosen because they represent varying levels of professional power and influence. The document analysis involves examining policy reforms, official ministry documents, research reports evaluating policy developments (from 2010 to 2022), knowledge databases, and information portals on ministry websites. This provided insights into the accumulation and dissemination of research-based knowledge. To understand the dynamics of political, scientific-administrative, and practical knowledge, 17 semi-structured interviews were conducted in 2022 and 2023 with ministry officials, stakeholder organizations, and researchers. Interviewees were selected to represent diverse perspectives, both within and outside the ministries, and to cover various organizations and agencies involved in the two policy areas. All interviews were audio-recorded, transcribed, and analyzed thematically using NVivo 12, focusing on the three knowledge types while also considering other relevant factors. The interviews aimed to understand evidence availability, relevance, collection, and use in relation to local actors. The overall approach is exploratory, given the limited existing research on the interaction between centrally defined evidence-based policies and the role of practical knowledge.

The analysis of active labor market policy revealed a process of evidence-based management where the Ministry of Employment, possessing a high policy capacity and facing low political conflict, identified and promoted evidence-based interventions. These interventions, focused on increasing early interviews with the unemployed and business programs, were implemented largely without significant resistance from public professionals. While this approach increased the pace of employment for some groups, it did not reduce overall costs or improve employment outcomes for less resourceful groups. This led to a policy shift in 2022, with plans to decentralize job centers. In contrast, the public school policy case demonstrated a re-politicization of evidence. The Ministry of Children and Education, despite having access to substantial educational research, struggled to implement evidence-based management due to teachers' professional autonomy and the lack of a direct link between evidence and easily measurable performance indicators. A nationwide reform aimed at improving student performance led to significant conflict with the Danish Union of Teachers, leading to a breakdown in negotiations and ultimately to the reform's failure to achieve its objectives. This case highlights the capacity of a powerful profession to resist and re-shape policy based on their practical knowledge and influence. The findings support a three-stage model: Stage 1 involves identifying evidence-based policies (primarily through political and scientific-administrative knowledge). Stage 2 is evidence-based management, where evidence is imposed on professionals, and Stage 3 involves re-politicization of evidence by professionals challenging policies based on their practical expertise.

The findings challenge the notion that practical knowledge is solely a source of error in evidence-based policy implementation. The study reveals the dual nature of practical knowledge: it can be used to implement evidence-based policies (as seen in active labor market policy) or to contest and reshape policies (as in public school policy). The three-stage model offers a dynamic framework for understanding the interaction between different knowledge types in evidence-based policy. The model highlights that the success of evidence-based policies depends not only on policy capacity and political context but also on the power dynamics between policy makers and professionals. The relative ease of implementing evidence-based interventions varies widely depending on the ability of professionals to challenge policies and the availability of mechanisms to link evidence to observable, measurable outputs. The study's findings have implications for evidence-based policy design, suggesting the need for greater collaboration and consideration of the perspectives and expertise of public professionals.

This article presents a three-stage model that captures the dynamic interplay between political, scientific-administrative, and practical knowledge in evidence-based welfare reform. The findings show that practical knowledge plays a crucial role, influencing both implementation and the potential for re-politicization. The success of evidence-based policy hinges on acknowledging and incorporating this dynamic interplay. Future research could explore the generalizability of the model across different welfare policy contexts and examine the strategies that can facilitate effective collaboration between policymakers and professionals in evidence-based policy-making.

The study's focus on two specific policy areas in Denmark limits the generalizability of its findings to other contexts. The time period covered (2010-2022) reflects a particular political and social climate; thus, findings may not fully capture the nuances of other periods. Despite the robust data collection, the subjective nature of interviews and document analysis might influence interpretation. Further research utilizing comparative case studies from diverse settings is warranted to expand upon the findings and refine the proposed model.