## 3 Results and Discussions
### The Possibility of Promoting Respondent's U-Turn to Improve the Population Disparities
Nodes 5 and 11 also hold promise to change to improve population disparities among the three metropolitan areas and other rural areas. At Node 5, although the contribution to the improvement of population sustainability was low due to a high ratio of elderly people, attachment to hometown was an important factor for enhancing U-turn motivations. In order to promote their U-turn migrations, measures are required to raise respondents' attachment to their hometowns. According to the findingsof previous studies, one strategy is to increase the opportunities for people to connect with their regional environments and resources, by providing financial aid or a social system to make their visits to their hometowns easier. Another is to remotely inform them of regional information such as good news or regional resources (e.g., through social networking service or internet). This may invoke pride for their hometowns in people and enhance their attachment. Furthermore, similar steps may also prove effective for potential U-turn migrants at Node 9, whose attachment to their hometowns conflicts with their attachment to the current residential locations. By contrast, the respondents at Node 11 had stronger attachments to their hometowns than to their current residences. These respondents' evaluations of the climate conditions in their hometowns were relatively high. Likewise, their evaluation of the ease of supporting their parents was also an important factor for their U-turn motivation. However, low evaluations of this living environment reduced their U-turn motivations. Although it is contrary to the results of other branches, it is assumed that respondents whose U-turn motivation were medium were preferentially extracted at Node 12. The rest were respondents at Node 11, for whom a higher evaluation of the transportation environment at their current residential places exerted a stronger influence. However, it is necessary to assess the effects of the evaluations of ease of supporting parents in order to plan countermeasures. A weak but positive correlation (r = 0.22, N = 474) was found between the U-turn motivations and the evaluations of this living environment in the hometown. This suggests that the better the environment for supporting parents in hometowns, the higher the respondents' U-turn motivations. The development of the conditions under which people can migrate to support their parents is important for this group. For example, recently in Japan, several local governments have started providing financial support to children when they migrate to their parents' cities of residence [57]. Living near parents also offers benefits for the children's generation as their parents can look after the grandchildren. The enrichment of these support systems may boost these people's decisions regarding a U-turn migration. For Node 11, it is necessary to develop the transportation environments in respondents' hometowns. However, many of the respondents in this group were living in bigger cities, such as ordinance-designated cities or the 23 wards of Tokyo; by implication, their hometowns tend to be smaller in size. It is not easy for these places to develop a level of transportation that competes with big cities. Thus, it is important to utilize the existing urban planning system, including restructuring of the previous transportation system, such as location normalization planning.