Even once the pandemic is resolved, it will not be the "end": How do we prepare for the long-term impacts?

Senior fellow, RIETI

On April 7, 2020, Prime Minister Abe declared a state of emergency, putting Japan's response to the COVID-19 pandemic on a new level. What are the likely outcomes of Japan's infection countermeasures? The author, who is neither an epidemiologist nor possesses any other relevant specialized knowledge, is unable to speculate on an answer to this question, but as a social sciences scholar, I would like to put forth a word of warning for the record.

Current discussions are focused on how to suppress spread of the infection. This is natural because Japan is teetering on the precipice of an explosive spread in infections. Nevertheless, with our remaining strength, we must also underpin this dialogue with a discussion that anticipates the situation after the pandemic has been resolved. That is the substance of this paper.

1918 pandemic

As has often been mentioned in relation to this pandemic, the first wave of influenza that broke out in North America and Europe in the spring of 1918 subsequently increased in virulence in the autumn of 2018, leading to a deadly second wave of the infection. There was even a third wave, which arose during winter at the beginning of 1919 and subsequently subsided. This is regarded as the oldest influenza pandemic in recorded human history. It is commonly referred to as the Spanish flu (an appellation that is an expedient historical convention despite the fact that the virus did not develop in Spain and current WHO guidelines state that the names of places or people are not to be used for designating infections).

The 1918 pandemic brought about heart-wrenching calamity worldwide. While estimates vary, it is believed that the virus infected one fourth of the global population and that pandemic-related deaths amounted to between 40 and 50 million people (the number in Japan is thought to have been approximately 340,000). This disease was characterized by high fatality rates among young adults. Approximately half of all deaths were adults in their twenties or thirties, and the death rate was particularly high for pregnant women (caution is necessary in that this pathology is very different from what has been observed in the COVID-19 pandemic).

Analysis of the 1918 pandemic's long-term impact

Over a period of approximately one year, the 1918 pandemic shook the entire world, and yet its effects did not dissipate after the infection subsided. In particular, the cohort that was affected in utero suffered physical and other effects in cases where the mother was infected (the health effect that fetuses suffer in utero and that have an impact even after birth is known in socio-epidemiology as the fetal origins hypothesis), and it is likely that these effects also impacted on the individual's later economic outcomes. The 2006 publication in which Almond advanced this idea forced much discussion on the topic. Almond (2006) focused on how the 1918 pandemic's destructive damage in the United States (an estimated 500,000 deaths) was concentrated during a short period of time in the autumn and winter of 1918, with the spread of the infection varying by state. Accordingly, Almond (2006) used US census data for each 10-year period from 1960 to 1980 to show that children exposed to influenza in utero suffered significant long-term effects even after birth and had a lower level of education, higher rates of physical disability, and lower socioeconomic status (it should be remembered that, as mentioned earlier, the 1918 pandemic was especially harmful to pregnant women) particularly when compared to pre- or post-pandemic cohorts.

Almond (2006) used data from the United States for analysis. Similar studies of the 1918 pandemic have verified these findings using data from Switzerland (Neelsen and Stratmann (2012)), Brazil (Nelson (2010)), and Taiwan (Lin and Liu (2014)). Comparable results have also been presented in studies with data from Britain in relation to the Asian influenza pandemic of 1957 (Kelly (2011)).

Furthermore, it has been shown that the pandemic not only affected children exposed in utero to the influenza virus, but also influenced how resources were allocated within household budgets. Parman (2015) demonstrated that, in cases where the child who was a fetus during the pandemic had one or more siblings, resources were more intensely allocated toward the oldest child, whose academic performance also turned out to be significantly higher. In other words a gap emerged between siblings.

However, there have also been strong rebuttals to Almond (2006). Brown and Duncan (2018) cast doubt on the statistical exchangeability of birth cohort in 1919 with pre- and post-pandemic birth cohorts. Cohorts exposed to the influenza tended to be born to families of lower socioeconomic status compared to those in unexposed cohorts. Moreover, fathers of the 1919 birth cohort were characterized by lower literacy rates, engaged in lower earning occupations, had lower socioeconomic status, and were otherwise different from fathers of surrounding birth cohorts. After controlling for such characteristics, Brown and Duncan (2018) found little evidence that individuals born in 1919 had worse socioeconomic outcomes in adulthood compared to surrounding birth cohorts.

However, Beach et al. (2018) disputed this finding by using data linking US population censuses to World War II enlistment records and city-level influenza data in order to re-examine Almond (2006) after controlling more rigorously for the attributes of fathers of the 1919 birth cohort and level of exposure to influenza. Beach et.al. (2018) argued that the fetal origins hypothesis, which Almond (2006) presented, is ultimately supported.

What will happen after the COVID-19 pandemic?

Once again caution must be exercised due to the fact that the pathology of COVID-19 is very different from that of the influenza virus (particularly the 1918 pandemic virus), and therefore these analysis results may not apply directly to circumstances after the COVID-19 pandemic subsides.

In addition, over a century has passed since 1918 when the Spanish Influenza pandemic began. The influenza virus was discovered in 1933 and medical developments have lowered the likelihood that socioeconomic vulnerabilities will exacerbate the harm from virus exposure. The level to which the social security system has developed is also considerable. Moreover, improvements have been seen in the public health environment in many countries, including emerging countries, and economic development has enhanced the state of nutrition. Therefore, it is certainly not a given that the fetal origins hypothesis will similarly affect future generations today.

Nevertheless, if we proceed with a detailed examination, a few commonalities can be found. At the current stage, although specific attributes of patients infected with COVID-19 are not that apparent, we should amass as much data as possible, even in the midst of this crisis, to increase the likelihood of creating effective future policy responses.

In addition to the unknown potential in utero effects of this virus highlighted in the fetal origins hypothesis, the virus and our responses to it are already having significant effects. For example, the simultaneous closure of elementary, middle, and high schools as well as other educational institutions throughout the country is highly likely to have some sort of effect on children's educational achievement. It is also anticipated that the economic uncertainty, which the parental generation is experiencing, will affect the selection of university candidates in 2020.

Furthermore, the degree to which the supply side of the economy is damaged as well as the extent to which the future outlook worsens is bound to have an effect on new graduates also as they look for and secure their first employment. Although it did not originate from the pandemic, the shock emanating from collapse of the bubble economy has had a persistent negative effect on the income of segments with lower educational backgrounds during what has come to be called the "employment Ice Age" (Genda et al. (2010)).

Because of these and other factors, we must utilize data to verify every conceivable possibility and formulate policies to prevent this pandemic from generating unfavorable conditions for specific groups or generations.

April 13, 2020
  • Almond, Douglas. (2006). Is the 1918 influenza pandemic over? Long-term effects of in utero influenza exposure in the post-1940 US population. Journal of Political Economy, Vol. 114(4), pp. 672-712.
  • Beach, Brian. Joseph P. Ferrie, and Martin H. Saavedra. (2018). Fetal shock or selection? The 1918 influenza pandemic and human capital development. NBER Working Paper 24725
  • Brown, Ryan, and Thomas, Duncan. (2018). On the long term effects of the 1918 US influenza pandemic. Unpublished Manuscript.
  • Genda, Yuji. Kondo, Ayako. and Ohta, Souichi. (2010). Long-Term Effects of a Recession at Labor Market Entry in Japan and the United States. The Journal of Human Resources, Vol. 45, No. 1, pp. 157-196
  • Kelly, Elaine. (2011). The Scourge of Asian Flu: In utero Exposure to Pandemic Influenza and the Development of a Cohort of British Children. Journal of Human Resources, Vol. 46, No. 4 (Fall), pp. 669-694
  • Lin, Ming-Jen, and Liu, Elaine M.. (2014). Does in utero exposure to Illness matter? The 1918 influenza epidemic in Taiwan as a natural experiment. Journal of Health Economics, Volume 37, September, pp. 152-163
  • Neelsen, Sven., and Stratmann, Thomas. (2011). Long-run effects of fetal influenza exposure: Evidence from Switzerland. Social Science and Medicine.
  • Nelson, Richard E.. (2010). Testing the fetal origins hypothesis in a developing country: evidence from the 1918 influenza pandemic. Health economics, Vol. 19(10), pp. 1181-1192.
  • Parman, John. (2015). Childhood health and sibling outcomes: Nurture Reinforcing nature during the 1918 influenza pandemic. Explorations in Economic History, Vol. 58, pp. 22-43

May 20, 2020

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