Research

PUBLICATIONS

• 1. Yoko Ibuka, Junya Hamaaki, "Income receipt, economic activities, and health: Evidence from ambulance transport patterns." Journal of Health Economics, forthcoming.  

  2. Shunichiro Konishi, Katsunori Masaki, Kyoko Shimamoto, Yoko Ibuka, Rei Goto, Ho Namkoong, Shotaro Chubachi, Hideki Terai, Takanori Asakura, Jun Miyata, Shuhei Azekawa, Kensuke Nakagawara, Hiromu Tanaka, Atsuho Morita, Norihiro Harada, Hitoshi Sasano, Ai Nakamura, Yu Kusaka, Takehiko Ohba, Yasushi Nakano, Kazumi Nishio, Yukiko Nakajima, Shoji Suzuki, Shuichi Yoshida, Hiroki Tateno, Koichi Fukunaga, "The relationship between long COVID, labor productivity, and socioeconomic losses in Japan: A cohort study." IJID Regions, 2025, 14, 100495. https://doi.org/10.1016/j.ijregi.2024.100495. 

  3. Dung Duc Le, Minh Thac Nguyen, Yoko Ibuka, "Intergenerational effects of education on child mortality: Evidence from the compulsory primary schooling law in Vietnam." World Development, 2025, 185, 106810. https://doi.org/10.1016/j.worlddev.2024.106810. 

  4. Junya Hamaaki, Yoko Ibuka, "The effect of inheritance receipt on labor supply: A longitudinal study of Japanese women." The B.E. Journal of Economic Analysis & Policy, 2024. https://doi.org/10.1515/bejeap-2022-0412. 

  5. Naomi Miyazato, Yoko Ibuka, Jun-ichi Itaya, "Peer effects on influenza vaccination: Evidence from a city's administrative data in Japan." Journal of the Japanese and International Economics, 2024, 74, 101335. https://doi.org/10.1016/j.jjie.2024.101335.

  6. Kyoko Shimamoto, Yoko Ibuka, "Socioeconomic disparities in risk perceptions and precautionary actions against COVID-19 among the working age population aged 18-59 in Japan: a cross-sectional study. " BMJ Public Health, 2024, 2:e00181. doi:10.1136/ bmjph-2023-000181. 

  7. Rong Fu, Dung Duc Le, Yoko Ibuka, "The impact of reducing formal care benefits on caregivers' well-being: evidence from Japan."  Review of Economics of the Household, 2024. https://doi.org/10.1007/s11150-024-09699-5. 

  8. Takayuki Ando, Yoko Ibuka, Rei Goto, Junji Haruta, Dung Duc Le, Seitaroh Fujishima, "Effect of influenza vaccine subsidies for older adults on vaccination coverage and mortality before and during the COVID-19 pandemic: an ecological study in Japan." Public Health, 2023, 224: 152-158. https://doi.org/10.1016/j.puhe.2023.08.031. 

     • Takayuki Ando, Yoko Ibuka, Rei Goto, Junji Haruta, Dung Duc Le, Seitaroh Fujishima, "Re: Letter to the editor of Public Health in response to "Effect of influenza vaccine subsidies for older adults on vaccination coverage and mortaltiy before and during the COVID-19 pandeimic: an ecological study in Japan."  Public Health, 2024, 227: e3-e4. https://doi.org/10.1016/j.puhe.2023.12.011.

  9. Hideki Terai, Makoto Ishii, Ryo Takemura,...., Yoko Ibuka,..., Koichi Fukunaga, "Comprehensive analysis of long COVID in a Japanese nationwide prospect cohort study." Respiratory Investigation, 2023: 61(6); 802-814. https://doi.org/10.1016/j.resinv.2023.08.008. 

  10. Dung Duc Le, Nekehia T Quashie, Martina Brandt, Yoko Ibuka, "Wealth inequalities in physical and cognitive impairments across Japan and Europe: The role of health expenditure and infrastructure." International Journal for Equity in Health, 2023, 22, Article number: 123.

  11. Dung Duc Le,  Yoko Ibuka, "Understanding the effects of informal caregiving on health and well-being: Heterogeneity and Mechanisms." Social Science and Medicine, 2023, 317, 115630. doi: 10.1016/j.socscimed.2022.115630.  

  12. Hongming Wang, Yoko Ibuka, Ryota Nakamura, "Mixing age and risk groups for accessing COVID-19 vaccines: A modeling study." BMJ Open, 2022, 12:e061139. http://dx.doi.org/10.1136/bmjopen-2022-061139.  

  13. Shinya Tsuzuki, Yusuke Asai, Yoko Ibuka, Tomoki Nakaya, Norio Ohmagari, Niel Hens, Philippe Beutels, "Social contact patterns in Japan in the COVID-19 pandemic during and after the Tokyo Olympic Games." Journal of Global Health, 2022,  Dec 3:12:05047. DOI:10.7189/jogh.12.05047. 

  14. Kyoko Shimamoto, Eoin McElroy, Yoko Ibuka, "Health inequity in pandemic anxiety about COVID-19 infection and socioeconomic consequences in Japan: A structural equation modeling approach." Social Science and Medicine Population Health, 2022, 20: 101269. https://doi.org/10.1016/j.ssmph.2022.101269.

  15. Kensuke Nakagawara, Ho NamKoong, Hideki Terai, ...., Yoko Ibuka,..., Koichi Fukunaga, "Comprehensive and long-term survey of COVID-19 sequelae in Japan, an ambidirectional multicentre cohort study: study protocol." BMJ Open Respiratory Research, 2021, 8: e001005. https://doi.org/10.1136/bmjresp-2021-001015.  

  16. Yoko Ibuka, Yui Ohtsu, "Socioeconomic status and the likelihood of informal care provision in Japan: An analysis considering survival probability of care recipients." PLoS One, 2021. https://doi.org/10.1371/journal.pone.0256107. 

  17. Yoko Ibuka, Yasumasa Matsuda, Keishi Shoji, Tsukasa Ishigaki, "Evaluation of regional variations in healthcare utilization." Japanese Journal of Statistics and Data Science, 2020, 3: 349-365. 

  18. Shun-ichiro Bessho, Yoko Ibuka, "Interdependency in Vaccination Policies among Japanese Municipalities." Health Economics ,2019, 28(2): 299-310. 

  19. Eric B. French, Jeremy McCauley, Maria Aragon, Pieter Bakx, Martin Chalkley, Stacey H. Chen, Bent J. Christensen, Hongwei Chuang, Aurelie Côté-Sergent, Mariacristina De Nardi, Elliott Fan, Damien Échevin, Pierre-Yves Geoffard, Christelle Gastaldi-Ménager, Mette Gørtz, Yoko Ibuka, John B. Jones, Malene Kallestrup-Lamb, Martin Karlsson, Tobias J. Klein, Grégoire de Lagasnerie, Pierre-Carl Michaud, Owen O'Donnell, Nigel Rice, Jonathan S. Skinner, Eddy van Doorslaer, Nicolas R. Ziebarth and Elaine Kelly,  "End-Of-Life Medical Spending In Last Twelve Months Of Life Is Lower Than Previously Reported." Health Affairs, 2017, 36(7):1211-1217. 

  20. Yoko Ibuka, Stacey H. Chen, Yui Ohtsu, Nobuyuki Izumida, "Medical Spending in Japan: An Analysis Using Administrative Data from A Citizen's Health Insurance Plan." Fiscal Studies, 2016, 37(3-4): 561-592.

  21. Yoko Ibuka, Shun-ichiro Bessho, "Out-of-pocket Payments and Community-wide Health Outcomes: An Examination of Influenza Vaccination Subsidies in Japan." Health Economics, Policy and Law, 2016, 11: 275-302. 

  22. Yoko Ibuka, Shun-ichiro Bessho, "Subsidies for Influenza Vaccination, Vaccination rates, and Health Outcomes among The Elderly in Japan. " Japan and the World Economy, 2015, 36: 56-66. 

  23. Yoko Ibuka, Yasushi Ohkusa, Tamie Sugawara, Gretchen B. Chapman, Dan Yamin, Katherine E. Atkins, Kiyosu Taniguchi, Nobuhiko Okabe, Alison P. Galvani, "Social Contacts, Vaccination Decisions and Influenza in Japan." Journal of Epidemiology and Community Health, 2016, 70: 162-167. 

  24. Yoko Ibuka, Meng Li, Jeffrey T. Vietri, Gretchen B. Chapman, Alison P. Galvani, "Free-riding Behavior in Vaccination Decisions: An Experimental Study." PLoS One, 2014, 9(1) : e87164. 

  25. David P. Durham, Eric M. Poolman, Yoko Ibuka, Jeffrey P. Townsend, Alison P. Galvani, "Reevaluation of Epidemiological Data Demonstrates That It Is Consistent with Cross-immunity among Human Papillomavirus Types." The Journal of Infectious Diseases, 2012, 206(8): 1291-1298.

  26. Yoko Ibuka, A. David Paltiel, Alison P. Galvani, "Impact of Program Scale and Indirect Effects on the Cost-effectiveness of Vaccination Programs." Medical Decision Making, 2012, 32(3): 442-446. 

  27. Gretchen B. Chapman, Meng Li, Jeffrey T. Vietri, Yoko Ibuka, David Thomas, Haewon Yoon, Alison P. Galvani, "Using Game Theory to Examine Incentives in Influenza Vaccination Behavior." Psychological Science, 2012, 23(9): 1008-1015. 

  28. Tamie Sugawara, Yasushi Ohkusa, Yoko Ibuka, Hirokazu Kawanohara, Kiyosu Taniguchi, Nobuhiko Okabe, "Real-time Prescription Surveillance and its Application to Monitoring Seasonal Influenza Activity in Japan." Journal of Medical Internet Research, 2012, 14(1):e14. 

  29. Daniel Jonas, Yoko Ibuka, Louise B. Russell, "How Much Time Do Adults Spend on Health-related Self-care? Results from the American Time Use Survey." Journal of the American Board of Family Medicine, 2011, 24(4): 380-390. 

  30. Meng Li, Gretchen B. Chapman, Yoko Ibuka, Lauren A. Meyers, Alison P. Galvani, “Who Got Vaccinated against H1N1 Pandemic Influenza? – A Longitudinal Study in Four U.S. Cities.” Psychology and Health, 2012, 27(1): 101-115. 

  31. Yoko Ibuka, Gretchen B. Chapman, Lauren A. Meyers, Meng Li, Alison P. Galvani, “The Dynamics of Risk Perceptions and Precautionary Behavior in Response to 2009 (H1N1) Pandemic Influenza.” BMC Infectious Diseases, 2010, 10:296.  

  32. Deborah Carr, Yoko Ibuka, Louise B Russell. "How Much Time Do Americans Spend Seeking Health Care? Racial and Ethnic Differences in Patient Experiences."Research in the Sociology of Health Care, 2010, The Impact of Demographics on Health and Health Care: Ethnicity and Other Social Factors, 28:71-98. 

  33. Jennifer L. Lund, K. Robin Yabroff, Yoko Ibuka, Louise B. Russell, Paul G. Barnett, Joseph Lipscomb, William Lawrence, Martin L. Brown. "Inventory of Data Sources for Estimating Health Care Costs in the United States." Medical Care, Supplement 1, 2009, Health Care Costs: Data, Methods, Future Directions, 47(7):S127-142.

  34. Louise B. Russell, Yoko Ibuka, Deborah Carr. "How Much Time Do Patients Spend on Outpatient Visits? The American Time Use Survey." The Patient, 2008, 1(3):211-222.

  35. Louise B. Russell, Yoko Ibuka, Katharine G. Abraham. "Health-Related Activities in the American Time Use Survey." Medical Care, 2007, 45(7):680-685.

  36. Naoyuki Yoshino, Sahoko Kaji, Yoko Ibuka. "The Stabilization of an Open Economy with Capital Controls: An Analysis Using Malaysian Data." Asian Economic Papers, 2003, 2(3): 63-83.