要旨：This talk will firstly review observed trends among public transport operators regarding fare polices and discuss that both simplification and “optimisation by differentiation” trends exist. If revenue and demand management optimal fares are desired, also in urban settings distance and route depending fares are increasingly an option due to new data collection technologies. This leads to modelling challenges such “hyperpaths with non-additive costs” which will be discussed in the second part. In the third part then the impact of new transport forms, in particular shared transport and “cheap taxis” is discussed. The competition and collaboration potential will be highlighted. The talk will close with some thoughts on how electrification of the transport system and vehicle to grid services might also impact fares and revenues.

要旨：In their model of monopolistic competition with firm heterogeneity and variable markups, Nocco, Ottaviano, and Salto (2014) show firm heterogeneity and markup pricing create distortions at market equilibrium, which can be removed by a first-best policy if a firm-specific per-unit tax/subsidy is available. This study provides an alternative first-best policy without adopting a firm-specific tax/subsidy. The first-best outcome can be decentralized through a uniform ad valorem production tax and a uniform per-unit production subsidy, accompanied by a lump-sum tax on consumers. This indicates that policymakers can design the first-best policy without observing firm private information in terms of productivity.

要旨：Most metropolitan areas in the U.S. have been developed around the automobile, making driving essential to accessing opportunities.  Despite high rates of driving, some adults do not drive.  A majority of non-drivers face significant barriers to driving, one of which is state driver’s license regulations that deny driving privileges to unauthorized immigrants. However, 15 states and the District of Columbia have adopted laws allowing unauthorized immigrants to acquire driver licenses and, therefore, to legally drive.  In this study, we draw on annual data from the American Community Survey from 2006 to 2018 to examine the relationship between the adoption of state driver’s licensing laws for unauthorized immigrants and changes in automobile commuting and commuting by public transit.  We focus on unauthorized Latinx immigrants in California, the state with the largest percentage of unauthorized residents.  We then test to see whether the effects are similar in other states that have recently adopted comparable driver’s licensing regulations. Many unauthorized immigrants in California have obtained driver’s licenses through Assembly Bill 60 (AB 60) allowing them to drive legally. Our analysis shows that AB 60 had a small positive effect on auto commuting and a small negative effect on transit commuting among unauthorized Latinx immigrants in California but, likely, little or no effect in states outside of California. Combined with its role in reducing hit and run accidents and potentially easing immigrants’ fears of police stops, the evidence suggests that AB 60 has contributed to the enhanced mobility and safety of unauthorized immigrants and their families.

要旨：神戸市全体の大規模交通シミュレーションを実行した結果、交通量に対して道の本数をプロットすると、冪的な関係に従うことが明らかとなった。その起源について数学的なモデルを立て、冪的な分布が生じた理由について考察する。また、阪神高速のETCデータを分析したところ、ODには強固な規則性が存在することが示唆されたが、2020年にはCOVID19の影響により規則性が破れている様子が観察されたため、これについても報告する。

《参考資料》

Umemoto and Ito, Journal of Computational Social Science, 2018

Umemoto and Ito, Journal of Computational Social Science, 2019

要旨：We construct a model in which there are oligopolistic firms that can influence the aggregate market conditions and monopolistic firms which cannot influence the aggregate market. We assume that both types of firms can conduct R&D investments to improve their productivities. When the R&D cost of oligopolistic firms is sufficiently lower than monopolistic firms, oligopolistic firms can survive as big firms, which can manipulate the market, dominate the market and conduct the larger R&D investments. We show that with the increase in the market size, the relative outputs and R&D investments of oligopolistic firms compared to monopolistic firms are raised, and consequently, the survival of big firms becomes easy. We show that there is a subsidy policy that enables the economy to achieve the second-best allocation.

論文ファイル

要旨：This paper explores how political, social, and economic regime changes affect the lifecycles of manufacturing plants, exploiting Japan’s transition from a feudal regime to a modern regime in the late nineteenth century as a natural experiment. Using plant-level data for 1902, including the foundation year of each plant, we explored how the experience years-size profiles of plants differ before and after the regime change. Plants were found to grow much faster after the regime change, and the acceleration of growth after the regime change was much greater for the plants in exporting industries and industries intensively using steam power. These findings suggest that access to markets and access to modern technologies were the channels through which the regime change affected the experience years-size profile of plants. Furthermore, long-term historical data and narratives on two plants support the results. We also present evidence on how the life-cycle size growth differs across space.

要旨：Pandemic of COVID-19 required to change our lifestyles to contain or mitigate the spread of infectious diseases. Various Non-pharmaceutical intervention (NPI) measures have been implemented in the situation that no effective treatment or vaccine has been established. New methods for monitoring the spread of infection have been proposed based on the recent technological and theoretical developments. In this talk, I review basics of mathematical models of infectious diseases and recent topics related with NPIs, and report and discuss some results on the effects of NPIs and the future perspective.