The early 1990’s marked a turbulent period in Japan’s economic history. We reconstructed the non-aggregated data for 660,000 worker samples of the 1992 Employment Status Survey into the estimated data for all 64,000,000 workers in Japan using this government survey’s method and conducted unique analyses on the regional inequalities of worker incomes from the perspective of individual and regional disparities. The following results were obtained: (1) Clear individual income inequalities existed in accordance with the social attribute of workers framework. The gender-specific processes by which individual inequalities emerged were detected by the causal inference method. For women, great disadvantages were identified in income and employment status compared to men. (2) Particularly for men, clear regional income inequalities were found by the framework of zone/urban hierarchical systems. Regional factors for inequalities were formed by two kinds of effects: the regionally uneven distributions of workers with different social attributes/categories (compositional effects) and those of high-income workers within the same attributes/categories (hierarchical effects). (3) Analyzed by the Theil index, the component rates by the regional factors to the overall inequalities among workers were 6% for men and 3% for women. (4) By an experimental regression analysis for worker samples, about one third of the inequalities for men and women were explained by regional and social individual factors of workers. Over half of the variations of worker incomes were not explained by the regression model (probably caused by private individual factors of workers). Some contemporary meanings were found from this study for 1992.

This study analyzed the spatial distribution of population and housing in Daejeon Metropolitan City, a regional central city in South Korea, from the perspective of diversity. The diversity index of each administrative Dong is calculated using the population census variables of age, household, and housing type in 2010 and 2015. Variables affecting diversity changes are the increase in the number of people aged 55 or older, the increase in single-person households, and the increase in condominium dwellings. Based on extracted variables, specific population- and housing type- areas of concentration are identified: aged 55 or older, single-person households, detached houses; and age group of 35–44, couples with children, condominium dwellings. The spatial distribution shows that aged 55 or older, single-person households and detached house concentrations are found in the eastern part of the city, mainly the old city area. In contrast, 35–44 years old, couples and children, and condominium concentration districts are found in the western part where the development of condominium complexes occurred. In Daejeon, an elderly population concentration area exists, which is predicted to expand further as the elderly population increases. Since condominium construction serves as a pull factor for 35–44 years old and couples with children, condominium-centered housing construction in old city areas can increase the possibility of preserving age and household diversity.

This study discusses the dynamics of migrants’ frontier society with the case of L Village in Riau Province, Indonesia, where oil palm cultivation is dramatically expanding. In the late 1980s, a private company developed a large oil palm plantation in the village, after which a large number of migrants from North Sumatra Province started moving to the village. The migrants’ purposes could be roughly divided into two aspects: the first was to start oil palm cultivation, and the second was to work at a company’s plantation or smallholders’ farmland. Interestingly, in L Village, landless plantation laborers could also buy land with their savings and start cultivating oil palm. Some of those initially poor migrants gradually expanded their farmland and finally became large-scale smallholders with more than 10 ha of farmland. Two conditions enabled migrants to grow to become large-scale smallholders: they had to start cultivating oil palm before and up to the 1990s when the land price was low, and they had to accumulate additional funds from other income sources such as running general stores or timber sales businesses. After the 2010s, when no more land was available in L Village, many migrants re-migrated to other frontiers in search of new land for oil palm cultivation. This indicates that these cyclical migrations are very characteristic in Riau Province as an unintended side effect of oil palm expansion.