Long-term health consequences of prenatal exposure to the Korean War

ABSTRACT

This paper investigates how in-utero exposure to the Korean War (1950–1953) affected health outcomes at old age. The probabilities of suffering from a particular type of functional limitation as well as having any disability were significantly higher in 2010 among the individuals born in 1951, who were in utero during the worst time of the war. The results of difference-in-difference estimations suggest that the magnitude of the adverse 1951 cohort effect on health is significantly larger for individuals whose places of birth were more seriously devastated by the war. Available evidence supports the hypothesis that the adverse long-term effects of in-utero exposure to the Korean War found in this study are unlikely driven by selection bias: the subjects of the 1951 birth cohort were not negatively selected in terms of parental characteristics in 1960.

KEYWORDS:

• Fetal origins hypothesis
• maternal stress
• prenatal exposure
• Korean War
• health outcome

Acknowledgements

I benefited from helpful comments of the participants of the APEBH conference, IAGG-ER 8th Congress, International Health Economic Association Conference, Korean Health Economics and Policy Association Conference, and seminar at Seoul National University. I thank J. Kim for making arrangements for using the micro sample of the 2010 census in the Korean Statistical Office and two anonymous referees for their insightful comments. Any remaining errors are mine.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1. The effect of an adverse shock to health in utero depends on the patterns of postnatal investments in health and other types of human capital. Thus, the relationship between early-life conditions and later health outcomes is likely to differ across periods and countries. The differences depend on income, quality of medical care, and educational system, political and social structures, as well as cultural and social norms.

2. The official estimate of civilian casualties during the three years of hostilities totalled 990,968, including 373,599 persons killed, 229,625 injured, 84,532 abducted, and 303,212 missing in South Korea alone (Chung, 2010).

3. This assumption is reasonable because there were no major events such as economic shocks, epidemics, or institutional changes differentially affect the 1950 to 1951 birth cohorts and those adjacent to it.

4. Since the establishment of the 38th parallel as the border between North and South Korea was an arbitrary decision of the United States based on military and political considerations, the geographic variations in war-caused damage sustained by civilians are perhaps exogenously determined.

5. A more accurate measure of the severity of wartime experiences is whether the mother of a person lived in the Central Region when the Korean War broke out. The place of birth of Korean War cohorts is a reasonably effective proxy of the mother’s place of residence at the beginning of the war (Lee, 2014).

6. The 2000 census offers information on functional limitations only for individuals aged 65 and older; the cohorts born during the Korean War birth cohorts were 50 or younger when the census was taken. The 2005 census provides the health variables for all individuals, but does not indicate the place of birth. The publicly available 2 per cent micro sample of the 2010 census does not offer variables on the place of birth.

7. The graphs for all types of limitations can be obtained from the author upon request.

8. All the coefficients of interest are jointly significant at the 1 per cent level for all the regressions reported in this paper.

9. The negative effect of being born in 1951 on the quality of occupation is not fully explained by the disadvantage in educational attainment of the cohort. Although the education factor is controlled, the 1951 cohort effect remains statistically significant.

10. In the case of males, the coefficient for the 1951 birth cohort remains significantly positive for all categories of functional limitations if socioeconomic variables are added, except ‘communication.’ For females, the 1951 cohort effect is statistically significant for five out of eight measures of health.

11. The results, not presented here, can be obtained from the author.

12. The magnitude of the estimated effect of in-utero exposure to the Korea War is considerably large. For example, the estimated coefficients of the double-difference term for male disability show that in-utero exposure to the war increased the probability of having a disability by 0.61 percentage points to 0.99 percentage points, about 5 per cent to 8 per cent of the sample mean.

13. Variables on parental characteristics should be added to the regressions to address this concern. However, census reports the information on parents only if they reside in the same household. As the survival of and co-residence with parents are selective, conducting analyses based on a sample of people living with their parents would be problematic.

14. Year-by-year regressions, where the dummy variable for each birth cohort born from 1947 to 1957 is included one by one, provide similar results. Graphic comparisons across birth cohorts also confirm the regression results.

15. The aggregate earning losses from lowered education is estimated at about 2.0 trillion won in 2010 (about 1.8 billion US dollars in 2010 value), not much smaller than the entire physical cost of the Korean War, estimated at 11.8 trillion Won in 2010 (Lee, 2014).

Additional information

Funding

This work was supported by the National Research Foundation of Korea Grant funded by the Korean Government [grant number NRF-2014S1A5A2A01011221].