The role of value judgment in the production of evidence for policy: lessons from development interventions in health and nutrition.

This thesis concerns the production and use of evidence, especially for policy improvement. It is my main thesis that science cannot avoid making value judgments when it comes to issues of evidence for policy use. But, more importantly, that value judgments even inform the drawing of conclusions on the basis of evidence. Whether or not the production of evidence can and should be done in a value-free way is a highly controversial claim involving many disputes. What matters is that the total body of evidence for evaluating a particular claim considers evidence for and against a claim from different relevant value perspectives. This requires a concerted effort to investigate all the best available evidence about a preferred course of action. This is an interdisciplinary topic, and I address it in an interdisciplinary way, with arguments from philosophy of social science, social policy, and political science, including the subdiscipline policy studies.