@techreport{oai:ir.ide.go.jp:00052962,
 author = {Hamanaka, Shintaro},
 month = {Feb},
 note = {application/pdf, IDP000835_001, The world is full of overlapping and nested regionalism. Why? This paper answers this question from the perspective of countries that aspire to leadership. We pay special attention to membership, which is a concept intrinsically linked to leadership via the key factor of “exclusion,” because the exclusion of rivals is necessary for a state to become a leader. Our main claim is that the creation of a regional group is a convenient and effective way to exclude rivals; hence regionalism proliferates. Borrowing ideas from the social psychology literature on the leadership aspirations of individuals, this paper develops theories of exclusionary regionalism, which explain countries’ effort to organize regional groups from which more powerful states are excluded. The underlying rationale is that, just like people called “dominance-oriented leaders” by social psychologists, countries value the prestige of leading a group, even a very small regional group.},
 title = {The World of overlapping regions},
 year = {2022}
}