## 3 Results and Discussions
### Structure of Respondents' U-Turn Motivation by Living Environments as Important Factors
All patterns of regional evaluations (only hometown, only current region, or the difference between both regions) were adopted as branch conditions. At almost all branches, if the evaluation of a living environment for the hometowns was lower or higher than that for the current residence, the U-turn motivation varied in direct association with the next branch destination. Moreover, there were five instances in which a high (5 or 4) or low (1 or 2) evaluation of hometowns or current residences were directly linked to lower U-turn motivation. In addition, we focused on the distribution ratio of U-turn motivation at each last node. At six nodes (Node 3, 5, 9, 11, 15, 19), the prevailing level of U-turn motivation was low. By contrast, the number of last nodes where the prevailing level of U-turn motivation was in the middle (Node 12, 18, 20) and high (Node 7, 13) were fewer. These results provide an understanding of the reason why spontaneous U-turn migrations do not occur frequently in the current conditions in Japan. There are other findings derived from the branching process. For example, at Node 15, the U-turn motivation was mostly low. However, the distribution ratio of U-turn motivation changed through the branching processes before the last node and was influenced by the living environments in the current residence and hometown. When the branch process developed up to the Node 6, approximately half the respondents indicated low U-turn motivation, due to the gap in their attachments to the regions. In the next steps, a better shopping environment in the hometown encouraged the U-turn motivation of the group. Finally, a better environment for visiting ancestral graves at the current place of residence decreased the U-turn motivation of the group. These results suggest that individuals' U-turn motivation is developed through the multilayered influences of the living environments in both regions. Previous studies also examined the influence of the living environments in hometowns on the U-turn motivation. However, their study designs did not sufficiently focus on the influences on current residences of individuals, as well as the multilayered influences of the living environments of both regions. Our study design did include such influences, which provided new findings on a multilayered decision process related to the U-turn motivation of people not presently living in their hometowns. Moreover, in this multilayered structure, two types of living environments emerged as important factors. The first type includes the living environments that should be developed to enhance U-turn motivations. The second includes the existing hometown conditions that should be maintained due to their appeal, or for not being deterrents for potential U-turn migrants. For example, for Node 3, the evaluation of Pleasantness of Climate was the former type of factor, and Attachment to Region was the latter factor. In this node, the negative evaluation of the climate condition in respondents' hometowns was a decisive factor for reducing their U-turn motivation, despite the fact that their attachment to the hometown exceeded their attachment to the current place of residence. However, only improving the problems of bad climate through developments for enhancing pleasantness may not be a sufficient measure to enhance their U-turn motivation. If less attention is paid for maintaining or enhancing the evaluation of the attachment, the evaluation would become lower, and the hometowns no longer meet all required conditions that are necessary to enhance U-turn motivation. This may rather reduce people's U-turn motivation. These findings quantitatively demonstrate a need for policies that promote U-turn migration, while simultaneously considering each environment in the migration process and the various environmental factors related to people's U-turn motivation simultaneously, including their ties to factors in their current places of residence.