Komamura, Kouhei



Faculty of Economics (Mita)



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  • Daily steps and healthcare costs in Japanese communities

    Okamoto S., Kamimura K., Shiraishi K., Sumita K., Komamura K., Tsukao A., Chijiki S., Kuno S.

    Scientific Reports (Scientific Reports)  11 ( 1 )  2021.12

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    Physical inactivity is a pandemic that requires intensive, usually costly efforts for risk reduction of related chronic diseases. Nevertheless, it is challenging to determine the effectiveness of physical activity in healthcare cost reduction based on existing literature. Therefore, this study aimed to investigate the impact of physical activity (daily steps) on healthcare costs utilising the data retrieved from a health promotion project (the e-wellness Project, held in three municipalities in Japan). Evaluating the effects of daily steps, measured by pedometers, on healthcare costs by a quasi-experimental approach among participants aged 40–75 years (about 4000 person-years of observation, between 2009 and 2013), we found that a one-step-increase in the annual average daily step reduced outpatient healthcare costs by 16.26 JPY (≒ 0.11 GBD) in the short run. Based on the assumption of a dynamic relationship between the health statuses in multiple years, the long-run effects of daily steps on healthcare costs were estimated at 28.24 JPY (≒ 0.20 GBD). We determined the health benefits of walking in a sample of middle-aged and older Japanese adults by our findings that an increase in step counts reduced healthcare costs.

  • Age, gender, and financial literacy in Japan

    Okamoto S., Komamura K.

    PLoS ONE (PLoS ONE)  16 ( 11 November 2021 )  2021.11

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    Objective The aim of this study is to investigate the association between financial literacy and age as well as gender differences in financial literacy. Methods We analyse a sample of 25,000 individuals from 'The Financial Literacy Survey 2016' conducted by the Central Council for Financial Services Information (Bank of Japan). The analysis focuses on the relationship of age and financial literacy as well as that of age and selfrated financial knowledge. To consider factors accounting for gender differences in financial literacy, we use the Blinder-Oaxaca decomposition method. To further our understanding of financial literacy, we conduct additional analyses on financial behaviour and attitude. Results Although age is associated with increased financial literacy (Men, β: 0.249, standard error [SE]: 0.030; Women, 0.354, SE: 0.026), the growth rate decreases among the older respondents (Men, β: -0.002, SE: 0.000; Women, -0.003, SE: 0.000). However, the association between age and self-rated financial knowledge among men moves in the opposite direction (Age, β: -0.021, SE: 0.009, Age2, β: 0.000, SE: 0.000). Furthermore, female respondents are likely to be less financially literate than their male counterparts (β: -0.586, SE: 0.095) due to gender differences in the distribution of the factors that affect financial literacy (specifically education), their responses to financial literacy, and the interactions of these effects. In contrast to knowledge-based financial literacy, financial behaviour and attitudes among women are more preferable to those among men, namely, more premeditated. Conclusion Financial literacy increases until about one's early 60s, after which it declines, while confidence in financial literacy reflects the inverse trend, especially among men. Additionally, men are more financially literate than women; however, these differences could be mitigated through education. Meanwhile, financial behaviour and attitudes among men are less premeditated. Thus, policies are needed that can help older adults with their financial decision- making, enhance women's financial literacy, and improve men's financial behaviours and attitudes.

  • Employment and health after retirement in Japanese men

    Okamoto S., Okamura T., Komamura K.

    Bulletin of the World Health Organization (Bulletin of the World Health Organization)  96 ( 12 ) 826 - 833 2018.12

    ISSN  00429686

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    Objective To estimate the average treatment effect of working past the current retirement age on the health of Japanese men. Methods We used publicly available data from the National Survey of Japanese Elderly, extracting a sample of 1288 men who were 60 years or older. Survey respondents were followed-up for at most 15 years for the onset of four health outcomes: death, cognitive decline, stroke and diabetes. By using the propensity score method, we adjusted for the healthy worker effect by incorporating economic, sociodemographic and health data in the form of independent variables. By calculating the differences in times to a health outcome between those in employment and those not employed, we estimated the average treatment effects on health of being in paid work past retirement age. Findings Compared with those not employed, those in employment lived 1.91 years longer (95% confidence interval, CI: 0.70 to 3.11), had an additional 2.22 years (95% CI: 0.27 to 4.17) before experiencing cognitive decline, and had a longer period before the onset of diabetes and stroke of 6.05 years (95% CI: 4.44 to 7.65) and 3.35 years (95% CI: 1.42 to 5.28), respectively. We also observed differences between employees and the self-employed: the self-employed had longer life expectancies than employees. In terms of years to onset of diabetes or stroke, however, we only observed significant benefits to health of being an employee but not self-employed. Conclusion Our study found that being in employment past the current age of retirement had a positive impact on health.

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • 格差・貧困の変動要因に関する実証研究


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • 所得・消費・資産・主観的データを用いた貧困基準の総合的研究


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator


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