Evidence-based review of legislation in Germany

The call for evidence-based review of legislation by the German Federal Constitutional Court is solidly based on German constitutional law. In Germany, both the legislative obligation of evidentiary evaluation of legislative facts and their inclusion into judicial review are generally accepted. However, there is no conclusive relationship between evidence-based legislation and the evidence-based review of legislation. Therefore, the beginnings of evidence-based review in the case law of the German Federal Constitutional Court date back to the formative era of the Court when the concept of evidence-based legislation was still non-existent or remained in a dormant state. The upswing of evidence-based review in Germany profits from the absence of parliamentary sovereignty in German constitutional law on the one hand and a very strong reading of the rule of law and fundamental rights on the other hand. Hence, evidence-based review has its legal basis primarily in the principle of proportionality and the principles of equality and non-discrimination, which approach the concept of rational lawmaking. However, as a rule, the Constitutional Court can confine itself to meta-evaluation of legislative facts. Owing to the balance of powers, the Court must respect a legislative margin of appreciation. The Court is only in exceptional cases obliged to conduct a complete factual examination. Since the taking of evidence by the Constitutional Court is only vaguely regulated, it enjoys considerable leeway. Although the Karlsruhe Court(1) has gained international reputation as a frontrunner of empirical review, on closer inspections many problems remain to be solved. In this respect, the article concentrates on criteria determining the gradation of evidence-based review, ranging from manifest error to strict scrutiny, and on the intricate problem of legislative prognosis. An unbiased analysis of evidence-based review must consider in addition the strategies of courts and investigate, in particular, whether and when they are neutral, partisan or pursue their own interests.