This study analyzes the individual treatment effects on the treated of the openings of Shinkansen-stations on municipal population in the postwar period using the Synthetic Control Method. The main findings are as follows. First, the effects of Shinkansen station opening are mixed positive and negative. Second, the treatment effects are positively correlated with the population at the opening of the Shinkansen. Third, the treatment effects have weakened over time, especially since the 1980s. Fourth, the treatment effects tend to weaken rapidly with increasing distance from the current ordinance-designated city, but the decline is not monotonous. This study complements studies on the estimation of the effects of transportation infrastructure investments analyzed by the Difference in Differences and instrumental variables methods.

The criteria used in location analysis have to be chosen according to the character of the users. The purpose of this paper is to reveal gender and generation gap using the exisisting multi-criteria location model. The single facility location models addressed in this paper accommodate multiple simultaneous criteria in a continuous space when the squared Euclidean distances between the facility and affected inhabitants are used. We identify the entire set of Pareto-optimal locations for eight prefectures in Japan using mobile spatial statistics. We reveal the magnitude of gender gap and generation gap of such prefectures by use of the areas and diameters of such Pareto-optimal locations.

Currently, 289 of the 465 members of the House of Representatives are elected through a single-seat constituency system. These 289 seats are allocated to each prefecture according to population, with 7 seats in Ibaraki Prefecture, 12 seats in Hokkaido, and 30 seats in Tokyo for examples. Existing studies discussed how to determine the electoral districts with the main objective of correcting the vote-value disparity. In this paper, we focus on the disharmony between electoral districts and living areas, and the today’s silver democracy due to the declining birthrate and aging population, propose mathematical optimization models for dealing with them, and report numerical results based on real data.