미국행정법과 사법심사에서의 행정청 존중 ― 미국연방대법원의 Kisor v. Wilkie 판결을 중심으로 ―

Although the constitutional principle of separation-of-powers has been carefully and deliberately established in modern nations under rule of law, legislative branch is faced with substantial challenges of legislative limitations of enacting general and abstract rules and implicating substantive expertise as the administrative state has evolved substantially today. Against this backdrop, there are some cases where ambiguous or vague legislations are established or amended by Congress, inevitably leading government agencies to rely on rule-making to supplement legislation and certain adjudication by having its own interpretation of statutes. When such rule-making or adjudication becomes the subject of judicial review, the judicial branch of the government would struggle to determine the standard and scope of review it should apply. Under such circumstances, the U.S. Supreme Court has long been maintaining judicial practices and following precedents of deference to an agency’s own interpretation by applying a lenient standard of judicial review on rule-making or adjudication. When the legislation established or amended by Congress is genuinely ambiguous, the U.S. Supreme Court has been adhering to ‘Chevron Deference’ since 1984, a deference doctrine to the agency’s own interpretation of the legislation to resolve the issue. Likewise, it has been following the case laws of ‘Seminole Rock Deference’ since 1945 and the ‘Auer Deference’ since 1997, which is a principle deferring to the agency’s own interpretation of its own rules and regulations established mainly as guidelines to follow within the agency and its subsequent adjudication when the legislation established or amended by Congress is genuinely ambiguous. The agency deference principle has been criticized by academic scholars, stating that it goes against the separation-of-powers principle in a way that the government usurps legislative power granted to Congress under the U.S. Constitution and that it renounces to exercise its judicial power to monitor the agency action. Recently, it has also faced with strong criticism by some justices of the Supreme Court, arguing that the agency deference goes against the U.S. Constitution and the Administrative Procedure Act (APA). The U.S. Supreme Court’s decision in Kisor v. Wilkie (2019) raises a classic argument under the U.S. Constitution and administrative law on which judicial review standard the court should be apply to determine the agency’s reasonable interpretation of its own rules and subsequent adjudication, when Congress defers rule-making power to the executive agencies under law and they establish their own rules accordingly. It is also a representative case that underlies controversies over Auer Deference debated in the Supreme Court. The decision presents the majority opinions upholding the Auer Deference and two other concurring opinions, and the latter contains a separate opinion substantially agreeing with the majority opinions and dissenting with the majority opinions. This study will provide a detailed annotation on the majority opinions and concurring opinions articulated in Kisor’s case and examine if the ruling over this case upholds the principle of agency deference. The bottom line is to determine the meaning of ambiguous or vague rules. Furthermore, it is important how to construe the requirements and limitations in applying Auer Deference and how to understand and interpret the APA. To this end, we will first review the meaning of ambiguous or vague administrative rules and the requirements and limitations of agency deference outlined in Kisor’s case. Next, we will analyze the major opinions in the aforementioned case by looking at the relationship between the principles of agency deference and the APA and the common law and whether or not they are reasonable. Apart from this, we will also explore whether the agency deference principle goes against the APA and undermines the common law principle. Moreover, we will discuss the difference between substantive rules and interpretative rules in rule-making and the bounds of agency deference. Also, we will review whether the so-called ‘Skidmore Persuasion’ in 1944 mentioned in the concurring opinion in Kisor’s case is essentially different from Auer Deference upheld by the majority opinions. The study will also provide an opportunity to examine the significance of Kisor’s case in the U.S. administrative law and present useful implications in Korean administrative law. The ruling in Kisor’s case clearly revealed that the Supreme Court’s simple argument of following the precedents of agency deference will no longer provide a basis for persuading opponents of agency deference doctrine, under the ground that it goes against the constitutional principle of the separation of powers or regulations under the APA. In the future, the controversy over similar cases will continue in the Supreme Court. It is expected to focus on reviewing whether the substantive requirements for applying agency deference principle to the agency’s rule-making, interpretation and adjudication are met, rather than being bound by the terms or names set forth in the precedent cases, including the Auer Deference. Another significance of the Kisor’s case is that it also serves as a meaningful reference in Korea for addressing conflict between the legislative and executive branch regarding delegating rule-making power to agencies and resolving issues regarding the standard and scope of judicial review on the agency's discretionary action.