LAW AND DISCRETION IN MONETARY POLICY AND IN THE BANKING UNION: COMPLEXITY BETWEEN HIGH POLITICS AND ADMINISTRATION

The controversy over the degree of judicial review of monetary policy decisions triggered by the contrasting Weiss judgments of the German Federal Constitutional Court and of the Court of Justice of the European Union invites an inquiry into the role of law in areas characterized by a high degree of political and technical complexity. This article singles out the structural conditions that qualify complexity in specific instances of decision -making: prognostic assessments, goal -oriented decisions, marked by uncertainty, legal indeterminacy, and discretion. These traits characterize both monetary policy decisions and some regulatory decisions taken within the banking union, such as the setting of minimum requirements for own funds and eligible liabilities (MREL) and the calculation of the leverage ratios of credit institutions (Livret A judgments). Irrespective of the very distinct formal -institutional legal frameworks of these two policy fields, in those conditions legality may be determined by the discretionary choices of the decision -maker. For this reason, they impact the court's deployment of legal principles, namely proportionality and careful and impartial examination. This cross -sector comparison sheds light on the relative specificity of monetary policy, and leads to rejecting the transposition of a distinction between "high politics" and "ordinary administration" to EU law, as a means of both explaining and guiding different degrees of judicial review in conditions of complexity. The different constitutional relevance of monetary policy decisions and of "ordinary" banking supervision requires not a distinction that can rationalize judicial review, but a full consideration of the role that the law must have in supporting non -judicial accountability.