Putting evidence-based lawmaking to the test: Judicial review of legislative rationality

ABSTRACTBoth at the European and at the Member State level, evidence-based law making is on the rise. So far, the attention has mostly gone to methods of ex ante evaluation used by the legislature. In this article, we argue that more attention should be paid to the role of courts as regulatory watchdogs. The CJEU seems to move in this direction by increasingly conducting a procedural (proportionality) review of legislation. However, the CJEU does not yet scrutinise the underlying data or the scientific evidence on which consultations, impact assessments and other forms of ex ante evaluation rest. This means that when these evaluations are based on poor quality data, this will also affect the CJEU’s judgement. For Dutch courts, the situation is different. They are so far unwilling to include ex ante evaluations or empirical data in a proportionality review of legislation, although the Advisory Division of the Council of State emphasises the principles of subsidiarity and proportionality in its policy-analy...