This paper argues that, despite a very large volume of management reform in the EU over the past quarter century or more, our knowledge of the impacts of these efforts is patchy and fragile. It calls on a number of key studies which each, in a different way, carries this same basic message. In the second part of the paper the reasons for this state of affairs are analyzed. One set of reasons is concerned with the considerable methodological difficulties of evaluating major reforms, which are commonly complex, evolving and spread out over time. A second set of reasons concerns the limited incentives for politicians and top officials to take a sustained interest in evaluation. A concluding reflection is that, while this basic situation is not likely to change, there are nevertheless ways in which the academic contribution to reform evaluation can be strengthened.
Keywords: Public management reforms, impact, context, design of reforms, political interest, changes in performance, time.