The COVID-19 pandemic and human fertility

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The COVID-19 pandemic and human fertility
Birth trends in response to the pandemic will vary according to socioeconomic conditions
By A. Aassve1,2, N. Cavalli2,3,4, L. Mencarini2,5,
S. Plach2, M. Livi Bacci6,7
The coronavirus disease 2019
(COVID-19) pandemic will have con-
sequences for human populations.
Worldwide, mortality levels are cer-
tainly affected. The worst-hit north-
ern Italian provinces recorded losses
of period life expectancy of 2 to 3.5 years
for men and 1.1. to 2.5 years for women, the
largest decline in life expectancy since the
1918–1919 influenza pandemic and World
War II ( 1). Similar patterns follow in other
countries (2). With the focus firmly on
deaths, the scientific debate
risks overlooking that pop-
ulation dynamics are also
shaped by fertility trajec-
tories. Throughout history,
spikes in mortality owing
to events such as wars, fam-
ines, and pandemics were
followed by changes in fer-
tility, resulting in fewer
births in the short term and
by recuperation in subse-
quent years (3). Economic
and social change triggered
by a pandemic is also likely
to influence childbearing
intentions and completed
fertility. How the COVID-19
pandemic will affect fer-
tility has implications for
the rate of population ag-
ing, shaping future health
challenges and economic growth potential
across the globe.
There are frequent claims that the ongo-
ing pandemic will result in a “baby boom.”
Couples, it is argued, spend more time with
each other and, as such, they are more likely
to procreate. The empirical evidence for
this is sparse. Instead, recent studies focus-
ing on the short-term fertility consequences
of natural disasters, such as earthquakes
and hurricanes, find that peaks in mortal-
ity are generally followed by birth troughs
within a year; whereas studies focusing on
a longer time frame, from 1 to 5 years fol-
lowing the event, have unveiled patterns
of increasing fertility (4). Drivers of these
medium-term rebounds are the desire of
parents to replace lost children, as well as
structural shifts in expectations on the sur-
vival probability of offspring. In the wake of
unexpected mortality shocks, fertility may
also take on a symbolic meaning, as new
births become a positive reframing mecha-
nism, signaling a return to normality.
A relationship between excess influenza
deaths and a 9-month lagged depression in
births was observed by Jacques Bertillon in
seminal studies on the impact of the 1889
influenza outbreak on the population of
Fran ce (5). This relationship was further
explored in the context of the largest pan-
demic of the last century, the 1918–1919
H1N1 influenza A pandemic (the so-called
“Spanish flu”). In the United States, it
caused a 13% drop in birth rates from 1918
to 1919 (6). Channels for adverse fertility
effects include the increased mortality and
morbidity of adults in reproductive age;
higher frequency of maternal mortality and
stillbirths; and slowdowns in conceptions,
owing to fear of infections and decreased
social mixing. As for subsequent positive
fertility effects, the literature disagrees on
whether the baby boom that followed in
1920 should be attributed to the direct ef-
fects of the pandemic or to the end of World
War I, or to a mix of both. Peace led to a
recuperation of postponed marriages and
childbearing after couples reunited, as well
as remarriage of war widows (7, 8).
Although heuristically useful, historical
comparisons suffer several limitations. In
particular, unlike the 1918–1919 influenza,
COVID-19 affects older people more than
other age groups. Therefore, the mortality
and morbidity of potential parents is not a
viable mechanism for negative short-run
fertility changes today. In addition, during
the COVID-19 pandemic, child mortality has
been negligible, removing one of the main
drivers of the fertility rebounds observed in
the combined mortality-fertility crises of the
Malthusian era. Moreover, the unfolding ef-
fect of the COVID-19 pandemic on fertility
will depend on the ways in which societies
have developed and at what stage they are
in the demographic transition, from regimes
characterized by high birth rates and lack of
contraception, to controlled and low fertility
(see the figure).
Over the past century, world fertility has
undergone major change. Although high
1Department of Social and Political Sciences, Università Commerciale Luigi Bocconi, Via Guglielmo Röntgen 1, Milano, 20136 Italy. 2Carlo F. Dondena Centre for Research on Social Dynamics
and Public Policy, Università Commerciale Luigi Bocconi, Via Guglielmo Röntgen 1, Milano, 20136 Italy. 3Nuffield College, University of Oxford, 1 New Road, Oxford, OX1 1NF, UK. 4Department of
Sociology, University of Oxford, 42 Park End Street, Oxford OX1 1JD, UK. 5Department of Management and Technology, Università Commerciale Luigi Bocconi, Via Guglielmo Röntgen 1, Milan,
20136 Italy. 6Scuola di Scienze Politiche ‘Cesare Alfieri’, Università di Firenze, Via delle Pandette 32, Florence 50127, Italy. 7Dipartimento di Statistica, Informatica, Applicazioni ‘Giuseppe Parenti’,
Università di Firenze, Viale Morgagni 59, Florence 50134, Italy. Email: arnstein.aassve@unibocconi.it
High-income
countries
Low- and
middle-
income
countries
Transition
economies
and urban
areas
Rural areas
in low-
income
countries
or
COVID-19
pandemic and
associated
distancing
measu res
Fertility
Population
size
Population
aging
Economic losses and uncertainty
Economic losses and uncertainty
Fertility
Population
size
Fertility or
Population
aging
Population
size or
Population
aging
Access to ART
Work-life balance
Access to contraception
Development
Access to contraception
Possible post-pandemic fertility trajectories according to regional income level
The social measures aimed at reducing coronavirus disease 2019 (COVID-19) infection may be expected to have different effects
on fertility, depending on societies’ development and stage of the demographic transition, and ultimately, on population density
and age distribution. ART, assisted reproductive technology.
370 24 JULY 2020 • VOL 369 ISSUE 6502
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birth rates remain the norm in the poor-
est rural areas of the world, high-income
countries, several transition economies, and
most urban regions within low- and middle-
income countries reached approximately
replacement fertility levels of 2.1 children
per woman. Some countries even plunged to
extremely low fertility rates of <1.3 children
per woman. The decrease in world fertility
broadly fits the long-established negative as-
sociation of development with fertility, even
if this pattern does not necessarily hold for
the countries at advanced levels of devel-
opment, where the relationship appears to
have reversed (9). On this basis alone, one
might conclude that setbacks
in development, owing to nega-
tive life expectancy and income
shocks caused by the COVID-19
pandemic, will lift fertility in
countries scoring below 0.85 to
0.9 in the Human Development
Index but reduce fertility in
highly developed countries.
Increased fertility in the developing world
would maintain high population growth,
aggravating challenges in food production,
unemployment, poverty, and public health,
thus hampering economic growth and push-
ing back the onset of the demographic divi-
dend. A further fertility fall in high-income
countries would accelerate population aging
and population decline, both of which are
major policy concerns.
In high-income countries, expansion in
women’s education has been one of the
most powerful drivers behind the sustained
fertility decline of recent decades. Here,
fertility is maintained through extensive
outsourcing of childcare. During the cur-
rent pandemic, however, prolonged school
closures and mandated physical distancing
have caused an immediate return to child-
care within the home. In as much as this
imposes a heavier burden on parents’ time,
the lockdown will result in lower desired
fertility and childbearing postponements
in the short term. Subsequent fertility will
also be affected by the ways in which par-
ents and couples share the additional time
devoted to childcare and housework dur-
ing the lockdown. Greater gender equity
in the division of domestic labor would re-
duce the burden on women and have ben-
eficial fertility implications (10, 11). The
lockdown will, however, have other imme-
diate effects on fertility. Given high mater-
nal age in high-income countries, assisted
reproductive technology (ART) is essen-
tial for many parents who want children.
During the lockdown, most ART cycles
were suspended or canceled altogether.
The eventual reopening of fertility clinics
will not easily offset lost cycles.
The shutdowns are resulting in large eco-
nomic losses. With high-income countries
set to experience the steepest fall (–6.1%
in 2020 according to the International
Monetary Fund, versus –1% for developing
economies), millions of households will be
affected. Given the irreversible nature of
childbearing and the substantial costs as-
sociated with child-rearing, unemployment
and lost income will necessarily reduce fer-
tility. This was the experience of the 2008
Great Recession, when overall fertility de-
clined, particularly in countries that had
the strongest economic downturns (12). In
addition, a stronger feeling of uncertainty
will make couples postpone any long-term
investments—children being prime exam-
ples—and therefore reduce fertility further.
Coping mechanisms for dealing with un-
certainty will consequently matter. There is
evidence that, in periods with unexpected
increases in economic uncertainty, fertil-
ity declines less in areas characterized by
stronger trust and social capital (13).
In low- and middle-income countries,
as the economy relapses, the question is
whether fertility will start to rise again,
thereby reversing recent decades of fertil-
ity decline. In the demographic literature,
there are two main economic explanations
for high fertility. One is that poverty in-
creases the benefits of unpaid child labor
in the family while bringing down the life-
long value of investment in education. The
other is that high fertility offers a form of
security for parents in their old age (14).
However, socioeconomic development and
increased rural-to-urban migration over
the past decades cut the percentage of peo-
ple living in rural areas to less than half.
These structural changes have altered the
opportunity costs of childbearing, leading
to smaller-family ideals as well as greater
legitimacy for modern contraception and
wider accessibility to the same. Urban
dwellers in large cities are more directly
exposed to economic downturns: Rising
unemployment and underemployment are
already leading to migratory displacement
and decreased purchasing power, with ad-
verse implications for childbearing. The
COVID-19 pandemic also forced family-
planning centers to temporarily close or
reduce their activities. The short-term ef-
fect of lost access to contraception may
include an increase in unwanted pregnan-
cies, with adverse health implications for
mothers and children, as seen in the recent
West African Ebola crisis (15).
Certainly, policy responses will play a
central role, by determining not only the
scope of the pandemic itself, but also its
social and economic fallout. In contrast
to the 2008 economic recession, there is,
this time around, a consensus that auster-
ity is not the answer. Yet, given the scale
of the COVID-19 pandemic, fertility de-
cline seems likely, at least in high-income
countries and in the short term. In low-
and middle-income countries, the fertil-
ity decline observed in recent
decades is unlikely to be funda-
mentally reversed by the pan-
demic. In contrast to transition
economies, most sub-Saharan
African countries are lagging
behind in the demographic
transition. Despite prospects
of economic hardship and pov-
erty, ongoing structural change will make a
reversal to high fertility unlikely. For these
countries, trends in international coor-
dination and protectionism will be a key
determinant for the revival of their export-
led economies, thus affecting, directly and
indirectly, the world’s demographics for
years to come. j
REFERENCES AND NOTES
1. S. Ghislandi, R. Muttarak, M. Sauerberg, B. Scotti,
medRxiv 10.1101/2020.04.29.20084335 (2020).
2. J. Goldstein, R. Lee, Demographic Perspectives on
Mortality of Covid-19 and Other Epidemics. Working
Paper 27043; www.nber.org/papers/w27043.pdf
(2020).
3. A. Palloni, Popul . Dev. Rev. 14, 145 (1988).
4. A. Nandi, S. Mazumdar, J. R. Behrman, J. Popul. Econ. 31,
267 (2018).
5. J. Bertillon, in Annuaire statistique de la ville de
Paris pour l’année 1890, 1892 101–132 (Imprimerie
Municipale, 1892).
6. S. Chandra, J. Christensen, S.-E. Mamelund, N. Paneth,
Am. J. Epidemiol. 187, 2585 (2018).
7. S.-E. Mamelund, J. Infect. Dis. 206, 140 (2 012).
8. K. Bloom-Feshbach et al., J. Infe ct. Di s. 206, 141 (2012).
9. M. Myrskylä, H.-P. Kohler, F. C. Billari, Nature 460, 741
(2009).
10. F. Goldscheider, E. Bernhardt, T. Lappegård, Popul . Dev.
Rev. 41, 207 (2015).
11. G. Esping-Andersen, F. C. Billari, Popul. Dev. Rev . 41, 1
(2015).
12. T. Sobotka, V. Skirbekk, D. Philipov, Pop ul. Dev. Rev. 37,
267 (2011).
13. A. Aassve, M. Le Moglie, L. Mencarini, Popul. Stud.
10.1080/00324728.2020.1742927 (2020).
14. J. C. Caldwell, Popul . Dev. Rev. 2, 321 (1976).
15. L. Sochas, A. A. Channon, S. Nam, Health Policy Plan. 32
(suppl. 3), iii32 (2017).
ACKNOWLEDGMENTS
This study was supported by funding from the European
Research Council under the European Union’s Horizon 2020
research and innovation programme, Institutional Family
Demography (IFAMID) grant agreement no. 694145. We
appreciate editorial assistance from S. Young.
10.1126/science.abc9520
“How the COVID-19 pandemic will affect fertility has
implications for the rate of population aging,
shaping future health challenges and economic
growth potential across the globe.”
24 JULY 2020 • VOL 369 ISSUE 6502 371
Published by AAAS
Downloaded from https://www.science.org on November 29, 2023

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The COVID-19 pandemic and human fertility
A. Aassve, N. Cavalli, L. Mencarini, S. Plach, and M. Livi Bacci
Science 369 (6502), . DOI: 10.1126/science.abc9520
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