Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-17T08:34:55.160Z Has data issue: false hasContentIssue false
  • English
  • Français

IMPACT OF THE 2011 EARTHQUAKE ON MARRIAGES, BIRTHS AND THE SECONDARY SEX RATIO IN JAPAN

Published online by Cambridge University Press:  06 February 2014

YURI HAMAMATSU ,
YOSUKE INOUE ,
CHIHO WATANABE  and
MASAHIRO UMEZAKI
YURI HAMAMATSU*
Affiliation:
Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Japan
YOSUKE INOUE
Affiliation:
Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Japan
CHIHO WATANABE
Affiliation:
Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Japan
MASAHIRO UMEZAKI
Affiliation:
Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Japan
*
1Corresponding author. Email: yhama@humeco.m.u-tokyo.ac.jp
Get access Rights & Permissions [Opens in a new window]

Summary

On 11th March 2011 a magnitude nine earthquake struck the Tohoku region of Japan. The earthquake resulted in a large tsunami and an accident at the Fukushima Nuclear Power Plant. Previous studies have suggested that demographic indices relating to reproduction and marriage change after such massive disasters (e.g. large earthquakes). The present study investigated whether the number of births, number of marriages and the secondary sex ratio (SSR) changed after the East Japan Earthquake. The monthly number of births (males and females, separately) and marriages in each prefecture in Japan from January 1997 to June 2012 were obtained from the Demographic Survey of Japan. An analysis was performed for three different geographic boundary units: the disaster-stricken area, the non-disaster-stricken area and the whole of Japan. In each unit, the numbers of births and marriages in a given month during the post-disaster period were predicted based on a regression equation estimated by the numbers of births and marriages in that month during the pre-disaster period. The numbers of observed monthly births and marriages during the post-disaster period were compared with the predicted figures. Differences between the observed and predicted numbers were determined by referring to the 95% confidence limits for the predicted mean number. The observed probability of a male birth in a given month during the post-disaster period was compared with a 95% confidence interval of a binominal distribution. In all three boundary units, the number of births was significantly lower than the predicted number by about 3–8% from nine months after the disaster, while the number of marriages in October 2011 was significantly lower than the predicted number by about 25–28%. In October 2011, the SSR in the whole of Japan had decreased from 104.8 (the predicted SSR) to 102.9. The number of births and marriages and the SSR decreased in Japan after the East Japan Earthquake irrespective of locality.

Type
Articles
Information
Journal of Biosocial Science , Volume 46 , Issue 6 , November 2014 , pp. 830 - 841
Copyright
Copyright © Cambridge University Press 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Asian Development Bank (2012) Addressing Climate Change and Migration in Asia and the Pacific. Asian Development Bank, Mandaluyong City.Google Scholar
Bongaarts, J. (2001) Fertility and reproductive preferences in post-transitional societies. Population and Development Review 27 (supplement), 260–281.Google Scholar
Bowlby, J. (1969) Attachment and Loss, Volume I: Attachment. Basic Books, New York.Google Scholar
Cabinet Office, Government of Japan (2012) The Economic Condition in Japan 2011–2012 [in Japanese]. URL: http://www5.cao.go.jp/keizai3/2011/1221nk/nk11.htmlGoogle Scholar
Catalano, R., Bruckner, T., Gould, J., Eskenazi, B. & Anderson, E. (2005) Sex ratios in California following the terrorist attacks of September 11, 2001. Human Reproduction 20(5), 1221–1227.Google Scholar
Cohan, C. L. & Cole, S. W. (2002) Life course transitions and natural disaster: marriage, birth, and divorce following hurricane Hugo. Journal of Family Psychology 16, 14–25.Google Scholar
Davis, D. L., Webster, P., Stainthorpe, H., Chilton, J., Jones, L. & Doi, R. (2007) Declines in sex ratio at birth and fetal deaths in Japan, and in U.S. whites but not African Americans. Environmental Health Perspective 115, 941–946.Google Scholar
Finlay, J. (2009) Fertility response to natural disasters: the case of three high mortality earthquakes. World Bank Policy Research Working Paper Series 4883. The World Bank, Washington, DC.Google Scholar
Fukuda, M., Fukuda, K., Shimizu, T. & Møller, H. (1998) Decline in sex ratio at birth after Kobe earthquake. Human Reproduction 13, 2321–2322.Google Scholar
Hansen, D., Møller, H. & Olsen, J. (1999) Severe periconceptional life events and the sex ratio in offspring: follow up study based on five national registers. British Medical Journal 319, 548–549.Google Scholar
Iwasawa, M., Kamata, K., Beppu, M. & Mita, F. (2012) The prediction of fertility considering the effect of the earthquake. In Ishii, F. (ed.) Incorporation of Foreign-Born Population and its Impact on Future Population Dynamics and Social Security in Japan [in Japanese]. Report of the fiscal year 2011 for Health Labour Sciences Research Grant, pp. 233–246.Google Scholar
Japan Meteorological Agency (n.d.) The 2011 Earthquake off the Pacific Coast of Tohoku. URL: http://www.jma.go.jp/jma/en/2011_Earthquake/2011_Earthquake.htmlGoogle Scholar
Kotozaki, Y. & Kawashima, R. (2012) Effects of the Higashi-Nihon earthquake: posttraumatic stress, psychological changes, and cortisol levels of survivors. PloS One 7(4), e34612.Google Scholar
Lyster, W. (1974) Altered sex ratio after the London smog of 1952 and the Brisbane flood of 1965. Journal of Obstetrics and Gynaecology of the British Commonwealth 81, 626–631.Google Scholar
McLeod, J. D. (1994) Anxiety disorders and marital quality. Journal of Abnormal Psychology 103, 767.Google Scholar
Matsuda, S. & Kahyo, H. (1994) Geographical differences and time trends in the seasonality of birth in Japan. International Journal of Epidemiology 23, 107–118.Google Scholar
Miura, T. (1987) The influence of seasonal atmospheric factors on human reproduction. Experientia 43, 48–54.Google Scholar
Mizuno, R. (2000) The male/female ratio of foetal deaths and births in Japan. The Lancet 356(9231), 738–739.Google Scholar
National Police Agency of Japan (n.d.) Damage Situation and Police Countermeasures Associated with 2011 Tohoku District – off the Pacific Ocean Earthquake. URL: http://www.npa.go.jp/archive/keibi/biki/higaijokyo_e.pdfGoogle Scholar
Okada, N., Ye, T., Kajitani, Y., Shi, P. & Tatano, H. (2011) The 2011 eastern Japan great earthquake disaster: overview and comments. International Journal of Disaster Risk Science 2(1), 34–42.Google Scholar
Prime Minister of Japan and His Cabinet (n.d.) Great East Japan Earthquake: Health and Safety. URL: http://www.kantei.go.jp/foreign/incident/health_and_safety.htmlGoogle Scholar
Retherford, R. D., Ogawa, N. & Sakamoto, S. (1996) Values and fertility change in Japan. Population Studies 50, 5–25.Google Scholar
Ruther, M. (2010) The Fertility Response to September 11th: Evidence from the Five Boroughs. Population Studies Centre, University of Pennsylvania, Philadelphia.Google Scholar
Statistic Bureau of Japan (n.d.) E-Stat: Portal Site of Official Statistics of Japan. URL: http://www.e-stat.go.jp/SG1/estat/eStatTopPortalE.doGoogle Scholar
Takagi, K. (2011) Abnormality and accidental diseases of pregnant women. In Aoki, Y., Hirasawa, M. & Kato, N. (eds) The System of Midwifery 3: Pathologic Physiology of Pregnancy and Delivery [in Japanese]. Nihon Kango Kyokai Press, Tokyo, pp. 43–76.Google Scholar
Takahashi, M. & Nagai, M. (2008) The seasonality of sex ratio [in Japanese]. Japan Journal of Hygiene 63(2), 461.Google Scholar
Torche, F. & Kleinhaus, K. (2012) Prenatal stress, gestational age and secondary sex ratio: the sex-specific effects of exposure to a natural disaster in early pregnancy. Human Reproduction 27, 558–567.Google Scholar
Udry, J. R. (1970) The effect of the great blackout of 1965 on births in New York City. Demography 7(3), 325–327.Google Scholar
White, L. & Rogers, S.J. (2004) Economic circumstances and family outcomes: a review of the 1990s. Journal of Marriage and Family 62, 1035–1051.Google Scholar
Yamada, M. (2007) Declining Birth Rate in Japan: Another Gap [in Japanese]. Iwanami Press, Tokyo.Google Scholar
Zorn, B., Šučur, V., Stare, J. & Meden-Vrtovec, H. (2002) Decline in sex ratio at birth after 10-day war in Slovenia: brief communication. Human Reproduction 17, 3173–3177.Google Scholar