Research News

May 14, 2024

  • Human Life and Ecology

New transit station in Japan significantly reduced cumulative health expenditures

Time series data and causal impact algorithm reveal the effectiveness of a new transit station over a four-year period

Graphical abstract: Health Expenditure Impact of Opening a New Public Transport Station: A Natural Experiment of JR-Sojiji Station in Japan

The new public transport station was significantly associated with the decrease in average health expenditures per capita by approximately JPY 99,257 over four years.

Credit: Haruka Kato, Osaka Metropolitan University (CC BY 4.0,

The declining population in Osaka is related to an aging society that is driving up health expenditures. Dr. Haruka Kato, a junior associate professor at Osaka Metropolitan University, teamed up with the Future Co-creation Laboratory at Japan System Techniques Co., Ltd. to conduct natural experiments on how a new train station might impact healthcare expenditures.

JR-Sojiji Station opened in March 2018 in a suburban city on the West Japan Railway line connecting Osaka and Kyoto. The researchers used a causal impact algorithm to analyze the medical expenditure data gathered from the time series medical dataset REZULT provided by Japan System Techniques.

Their results indicate that opening this mass transit station was significantly associated with a decrease in average healthcare expenditures per capita by approximately 99,257.31 Japanese yen (USD 929.99) over four years, with US dollar figures based on March 2018 exchange rates. In addition, the 95% confidence interval indicated the four-year decreasing expenditure of JPY 136,194.37 ($1276.06) to JPY 62,119.02 ($582.02). This study’s findings are consistent with previous studies suggesting that increased access to transit might increase physical activity among transit users. The results provided evidence for the effectiveness of opening a mass transit station from the viewpoint of health expenditures.

“From the perspective of evidence-based policymaking, there is a need to assess the social impact of urban designs,” said Dr. Kato. “Our findings are an important achievement because they enable us to assess this impact from the perspective of health care expenditures, as in the case of JR-Sojiji Station.”

The findings were published in Journal of Transport & Health.


Haruka Kato received funding from JSPS Kakenhi (grant number 21K14318), the Osaka Metropolitan University Strategic Research Grant for Young Researchers (OMU-SRPP2023_YR05), the Asahi Glass Foundation (Research Grants for Sustainable Future (Proposed Research), and the JST COI-Next (JPMJPF2115).

Paper Information

Journal: Journal of Transport & Health
Title: Health expenditure impact of opening a new public transport station: A natural experiment of JR-Sojiji station in Japan
DOI: 10.1016/j.jth.2024.101808
Author: Haruka Kato, Taisuke Ichihara, Kenta Arai
Published: 9 April 2024


Haruka Kato

Graduate School of Human Life and Ecology
E-mail: haruka-kato[at]

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