A Scoping Review and evidence maps of Defra’s environmental policy evaluations

Policy evaluations are essential for understanding the effectiveness of Government actions and providing lessons that can inform future policy decisions and delivery. 

This report reviews all of Defra’s published evaluations that are publicly available, dating back to 1997. It explores the size and characteristics of this evidence base, relating it to the ten goals of the England Environmental Improvement Plan 2023. 

The review shows that a large proportion of the evaluation evidence base is focussed on agri-environment schemes and their contributions to a small number of the ten goals. Some goals, such as minimising waste and mitigating and adapting to climate change, have little associated evidence of policy efficacy. Most of the evaluations focus on impacts and value for money. None of the studies contained evidence of independent or consistent replication of impacts resulting from a particular policy. 

The analysis in this report is also extended to a broader set of evidence sources used in different assessments such as policy appraisals and impact assessments. It concludes by highlighting the need to fill evaluation evidence gaps, and synthesise existing evidence, to strengthen the design and implementation of key policies intended to deliver the government’s Environmental Improvement Plan targets and commitments. 

Evidence maps

Two evidence maps have been produced to illustrate the findings of the project and to provide an accessible way to navigate to the underlying sources. They show types of evidence produced by different policy areas and which of the Environmental Improvement Plan goals they relate to. Key information and links to the sources can be seen by clicking on the bubbles in each cell.

Evaluation evidence (opens in new window)
Assessment evidence (opens in new window)


The UK Centre for Ecology and Hydrology were commissioned by the Office for Environmental Protection to undertake a Quick Scoping Review of Defra’s evaluations. The views provided in this report are those of the UK Centre for Ecology and Hydrology and do not represent the opinion of position of the OEP. Some of the analysis in this report was used to inform the OEP’s report Progress in improving the natural environment in England 2021/22.