Functions of the Proportionality Principle in Japanese Administrative Law

The proportionality principle (hereafter, the PP) was imported from Germany into Japanese administrative law during the interwar period. The Japanese Supreme Court has never expressly mentioned the principle itself in the opinion of the court except as an obita dictum. There are, however, several judgments that may be understood as the application of the PP.This essay questions whether the principle functions “outside” or “inside” of administrative discretion and whether it performs necessity control or balancing control. It also stands upon the premise that administrative discretion takes place in the process of the application of the law in the narrower sense, distinguished from the interpretation of law and from bare fact-finding, both of which are reserved for the judiciary.Regarding necessity control, the purpose-means construction as the core of the PP is self-evident. As for balancing control, the feature of the PP is that a particular interest is placed on one side of the scale and compared with various other interests. The Supreme Court is rather reluctant to perform such types of dichotomic balancing, but does so in certain cases.Whether such balancing is appropriate depends upon a determination of the desirable degree of judicial review, as well as an understanding of the legal structure in the relevant field. While such dichotomic balancing will provide an effective tool for judicial control, it also presents the risk of making diverse interest structures among various stakeholders invisible