The normative theory of government discretion in relation to both lawmaking and administrative adjudication, which is one of the central elements of planning law, has yielded a wealth of valuable insights based on an analysis of a long and extensive case law history. However, up to now little attention has been paid to the fact that the doctrine of reasonable commensuration ( Abwägungsgebot), which is derived from the principle of proportionality, makes certain methodological demands, particularly pertaining to predictions and value judgments, demands that cannot be sufficiently dealt with by using only natural language. In view of the gulf between these requirements and their implementation, Ekkehard Hofmann studies the potential usefulness of the numerical methods, developed in economic decision theory for carrying out the overall assessment that is necessary for making balanced decisions and communicating their rationale.