Why have some autonomous territories ceased to exist by opting to become fully sovereign states while others have remained as partially independent polities under the ultimate sovereignty of their parent states?

Aside from having state-like structures and institutions in place that, theoretically, could make a transition into sovereign statehood easier from a practical point of view, what additional factors within the autonomous territories could provoke critical levels of secessionism and ultimate secession? Previous research has shown that factors pertaining to territory or group distinctiveness - such as linguistic and religious distinctiveness, geographical detachment and distance from the parent state along with a history of lost internal autonomy or sovereign statehood - could influence such movements and outcomes. Moreover, research has shown that factors concerning territory or group viability - such as relative economic performance, possession of natural resources, population and land area size - might contribute. If factors related to distinctiveness and viability coincide, the risk of secessionism and secession could increase even further.

This study applies a mixed-methods approach with statistical analysis of 53 autonomous territories in existence from 1901 to 2020, during which 11 ceased to exist and became sovereign states, and complementary case study analysis on one autonomous territory that has made this transition and on one that has not. The purpose is to ascertain whether factors related to distinctiveness and viability are indeed significant for explaining instances in which autonomous territories have seceded from their parent states, and to identify the specific factors that are especially influential. The findings suggest that ethnic distinctiveness in terms of language and religion combined has, to some extent, contributed to instances of autonomy failure by secession. However, the primary contributor to such outcomes according to the results is relative economic performance, particularly if the autonomous territory is less prosperous than its parent state.