Impact Assessment Before Courts Evidence-Based Policymaking Meet Judicial Review

In line with the principle of separation of powers, policy makers and courts have very different jobs. Yet, their respective inputs to the fabrics of government are not totally exclusive but complementary to one another: the output of the former's work, i.e. regulation, is subject to the scrutiny of the latter, through judicial review. Hence, the question arises whether and how the increasing use of impact assessment (IA) by policymakers in the preparation of policy proposals may affect courts when called upon to judge the legality of those initiatives and what this may entail for the legal system. This paper explores the actual consequences stemming from the progressive integration of IA within the judicial context. It will do so on the assumption that what IA has to offer courts is more than what courts may offer to IA: judicialization. Today it is indeed a truism to say that the act of judging involves more than the application of legal rules to individual cases. Thus, it will be demonstrated that while IA is not itself a procedural mechanism (like casting a vote or asking for advice) for making decisions, it provides – regardless of its formal legal status – substantive, and in some jurisdictions determinative, input into the legal process to the point of transforming it