What did the Republic of Korea and Japan mean by the term “joint development” in their 1974 agreement?

This paper examines what Korea and Japan meant by the term “joint development” in their Joint Development Agreement of 1974, which is the first instrument that the two states must rely on when launching plans for joint development. This research has practical relevance because a number of activities taking place concerning the joint development since the 2000s have revealed ambiguities under the Agreement. Specifically, are two types of activities conducted by non-concessionaires since 2000s—seismic survey and re-analysis of the previously collected research data—part of “joint development” under the Agreement? If not, what rules apply to the activities not regulated by the Agreement? This paper answers these questions by arguing that the Agreement does not regulate all activities related to “joint development” between Korea and Japan, and that Article 83 (3) of the UN Convention on the Law of the Sea applies to those activities not covered by the Agreement. This paper contributes to clarifying the scope of “joint development” under the Agreement and the latter's relationship to Article 83 (3) of the UN Convention on the Law of the Sea.