## 4 Conclusions  
### Summary of Study and Applicability of Findings  
This study involved a survey of respondents across Japan to arrive at suggestions for developing the regional living environments to promote people's spontaneous U-turn migrations. Our final goal was to provide suggestions for the improvement of population disparities in the whole of Japan by people's U-turn migrations. Our analyses focused on the relationships between respondents' evaluations of the living environments and their disposition toward U-turn migration. The questionnaire included questions related to living conditions. Using a decision tree analysis of the responses to these questions, we determined the living environments that affect people's U-turn motivations, and the kinds of development that may spur actual return migration. In the decision tree model, respondents were classified into eleven groups of members with similar demographic features and requirements for regional living environments. The results indicate a multilayered relationship between U-turn motivation and the evaluations of various living environments. By adopting this approach, we were able to determine not only the factors with some potential for promoting U-turn migration, but also factors that may prevent U-turns. One of our important findings was that respondents' U-turn motivations were affected by not only their evaluation of the living environments in their hometowns, but also by their evaluations of the current places of residence. In several instances, the current place of residence worked independently from the conditions in the hometown; however, in other cases, they interacted and influenced U-turn motivation. Through quantitative analyses and interpretations, this study partly explains people's decision-making processes for U-turn migration. The influence of individual living conditions in the decision tree indicates that enhancing the evaluation of the attachment to regions and the climate were indispensable for promoting people's U-turns. The differences in evaluations of these items strongly altered the tendency toward U-turn migration, appearing as the first branch condition from Node 0 or Node 1. In addition, the living environments related to family properties and relationships were also important factors for U-turn, especially for the eldest sons and their families. In Japan, the eldest son and his household are generally responsible for caretaking of his elderly parents, along with the inheritance and management of parental properties; these properties and relatives were often located in the respondents' hometowns. These results add quantitative evidence to the findings of previous studies that used qualitative approaches. Regarding the distribution ratio of the U-turn motivation for each group, motivation was low over half the decision tree groups. Although several groups had high U-turn motivations, their motivations tended to encourage the population disparities as their return migration would take them to cities with larger populations. Large cities tended to receive high evaluations because of their favorable transportation environments and shopping opportunities. In conjunction with these results, living conditions related to convenience sometimes became critical factors for reducing U-turn motivation. The case of shopping environment for respondents at Node 9 is an example; however, their potential U-turns may significantly contribute toward the improvement of population disparities, as many of them would return to rural provincial areas or smaller cities. Other groups, such as Nodes 5 and 11, had more respondents whose hometowns were located in rural provincial areas or smaller cities. The U-turn migration of respondents at these nodes can also bring improvements to population disparities. For these groups, the living environments of which the evaluations depended on the city size were not included or did not represent as critical deterrents to U-turn motivations.