THE PROBLEM ISN’T
OVERPOPULATION
AND THE FUTURE MAY BE
DEPOPULATION
by Dr. Ni ch olas Eberst a d t
T
HE CONVENERS OF THIS CONGRESS ASKED ME TO SUMMON
THE DARK POWERS OF DEMOGRAPHY TO FORETELL THE WORLD
POPULATION
SITUATION
IN
THE
COMING
CENTURY.
I
MUST
CONFESS THAT I WILL NOT BE ABLE TO DO SO BECAUSE WE HAVE NO
RELIABLE WAY OF FORETELLING HOW MANY BABIES CURRENTLY UNBORN
HUMANS ARE GOING TO HAVE. I WILL PRESENT TO YOU A SCENARIO FOR A
P EA K I NG OF GLO BAL POPULATION IN THE NEXT CENTURY AND A LO NG - T E R M
DECLINE THEREAFTER. SUCH A SITUATION IS ENTIRELY PLAUSIBLE.
F I R ST, L E T ’ S TA K E A LO O K AT
the twentieth-century population
exp losion. Between 1900 and now,
the wo r l d ’s populatio n has ro u g hly quadrupled from about 1. 6
billion in 1900 to about 6 billion
t o d a y. But the wo r l d ’s population
in our century did not explode
because human beings suddenly
started breeding like ra b b i t s ;
world population exploded beca u s e
humanity finally stopped dying
l i ke flies. During our century,
l i fe expectancy has more than doubled, from perhaps 30 ye a rs
a round 1900 to about 65 ye a rs
t o d a y. That health explosion is the
rea son for our great increase in
population numbers. But over th e
century we’ve also seen something
else. We’ve witnessed a phenomenon of long-term, steady declines
in fe r t i l i t y. This process actually
began two centuries ago, in Fra n c e
at the time of the Fre n ch Re vo l ution, and subsequently spre a d
a c ross the globe.
P rojections by the U.S. Bure a u
Marriage & Families
of the Census suggest that as of
1998 there we re about seve n t y
countries and territories aro u n d
the globe where fertility levels, if
continued, would eventually lea d
to a peaking and a d ecline of
po pulation (bar ring im migra t i o n ) .
We call this “sub-re p l a c e m e n t
fe r t i l i t y.” By 1998 abo ut 44
p e rcent of the wo r l d ’s population
was living in countr ies with s ubreplacement levels of fe r t i l i t y.
M o re ove r, in much of the wo r l d
w h e re above - replacement ch i l dbearing still pre vai ls, dra m a t i c
declines in fertility levels are currently underwa y. Rapid fe r t i l i t y
decline is occuring in som e surprising places. Ta ke Iran, fo r
e xample. Between the time of the
I ranian Re volution in the late
1970s and today, fertility leve l s
h a ve dropped from seven to under
t h ree births per woman per lifetime. Sub-Saharan Africa and the
Middl e East are said to be are a s
re s i stant to ferti lity re d u c t i o n s .
But there are coun tries in the
Middle East that have alre a d y
experienced almost a 50 perc e n t
d rop in fertility over the past
g e n e rati on. There are also countries in Africa that are beginni ng
a rapid fertility decline.
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With all this in mind, let’s take
significant would be the qu e st i o n and old er for every child under
a look at the United Na tio ns “ low
of pension burden in low- i n c o m e the age of five in those s ame lowvariant” world population p ro j e ccountries. The more deve l o p e d income areas of the worl d. We’d be
tions. By this set of projections, the
countries, after al l, became rich in a world wh e re there would be
United
Nations
Po p u l a t i o n
b e fo re they became old. In this m a ny more gra n d p a rents than
g ra n d ch i l d ren. We could get
D i v i s i o n, a group of h onori nto a new situation, one
able st a t i sticians within the
T H E W O R L D ’ S P O P U L AT I O N
n e ver witnessed befo re: the
UN Secretariat, traces o ut a
emergence of societies in
peaki ng of world popula tio n
I N O U R C E N T U RY D I D N O T
w h i ch the majority of ch i la round the year 2040, and
E X P LO D E B E C A U S E H U M A N
d ren would have no blood
then a subsequent population
b ro t h e rs, or sist e rs, or cousins,
decline. This is, cours e , t he
B E I N G S S U D D E N LY S TA R T E D
or uncles or aunts, societies in
“ l ow va r i a n t ” – j u st one of
BREEDING LIKE RABBITS;
w h i ch their blood re l a t i ve s
t h ree alternatives curre n t l y
a re all ancest o rs.
o u t l i n e d . But I want to show
This is not a totally
you that it’s not at all an
remote possibility. For exa mimplausible on e. Re a ch i n g
ple, if the current Italian
depopulation would simply
l e vels of fertility carry on fo r
re qu i re a conti nuation of
s i mp ly another genera t i o n ,
e x i sting trends for another
less than 10 percent of the
quarter century. What wo u l d
population would have both
a peaking and subsequ e n t
cousins and siblings. How
decline of world population
would a world work in which
por tend? I will how you thre e
t h i s t ra n s formation occurre d ?
implications of this . The first ,
I confess that as a low l y
i n e v i t a b l y, would be a ra p i d
social sci entist, my imaginaaging of the wo r l d ’s population cann ot st re t ch
fa r
tion. In the past, the median
enough to imagine thi s sort
age for the wo r l d ’s population
of world. But my imagina tion
has been between 20 and 25
may be s orely tested, because
ye a rs. It is now about 26
this pro s p e c t i ve depopulati on
ye a rs. By 2050, the median
that I have outlined could
age for a depopulating globe
occur within th e next 40
would be about 42 ye a rs. In
ye a rs. This means that m ost
the more developed re g i o n s
of the peopl e curre n t l y
the median age of population
a l i ve on the planet could
Photo Credit Comstock, Inc.
would be over 50. That is to
l i ve to experience and see
say: for every person under
the consequences of depoputhe age of 50, there would be
W O R L D P O P U L AT I O N E X P LO D E D
latio n and cope wi th them.
someone over the age of 50. A
B E C A U S E H U M A N I T Y F I N A L LY
The demographic specter
complete tra n s formation of
haunting humanity tom orrow
S T O P P E D DY I N G L I K E F L I E S .
the profile of the wo r l d
ma y turn out to be depopulawo uld thus occur.
tion.
With the population explosion of the elder ly there would be
vision of the future, there are
a tremen dous change in what we
m a ny p laces that would become Nicholas Eberstadt, Ph.D. D r.
E b e rstadt is a re s e a rcher with the
co uld call the “pensio n burd e n , ”
old befo re they become rich.
the ratio of peo ple 65 and ol der to
F i n a l l y, we would see changes in American Enterprise Institute in
so-called working age populations
the demographic balance betwe e n Washington, D.C., and the Harvard
of 15 to 64. In Japan, for every 10 0
g e n e rations. Around 1950 there Center for Population and Developp e rso ns of working age, there
we re about four ch i l d ren under ment Studies in Cambridge, MA.
would be 70 people over the age
th e age of five for every person 65 He earned his Ph.D. at Harvard
of 65. How pension syst e m s
or old er in the low-income re g i o n s Un i v e rsity and an M.Sc. from the
would operate in such a worl d is
of the world. In this set of pro j e c- London School of Economics.
an open qu e stion. But even more
tions we would s ee four people 65
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