The 1700s in Europe
are often referred to as the Age of Enlightenment. It was a time, we'd come
out of the Renaissance. We'd rediscovered science
and reason and in the 1700s, we saw that come about with
even more progress of society. As we exit the 1700s and
enter into the 1800s, we start having the
Industrial Revolution. And people saw the steady
march of human reason, of human progress. And because of this, a
lot of people were saying, hey, humanity will
continue to improve. It will improve
forever, to a point that poverty will go away. We will turn into this
perfect utopian civilization without wars, without
strife of any kind. And there was something
to be said about that. You had significant
improvements. In fact, you had even
more dramatic improvements once the Industrial
Revolution started. But not every one in the
late 1700s was as optimistic. And one of the more famous
not-so-optimistic people was Thomas Malthus,
right over here. And I will just
quote him directly. This is from his "Essay on
the Principle of Population." "The power of population
is so superior to the power of the earth to produce
subsistence for man, that premature death must,
in some shape or other, visit the human race." Very uplifting. "The vices of mankind are
active and able ministers of depopulation. They are the precursors in
the great army of destruction, and often finish the
dreadful work themselves. But should they fail in
this war of extermination, sickly seasons,
epidemics, pestilence, and plague advance in
terrific array, and sweep off their thousands
and tens of thousands. Should success still be
incomplete, gigantic, inevitable famine
stalks in the rear, and with one mighty blow
levels the population with the food of the world." So not so uplifting of a
little quote right over here. But this was his general sense. He lived in a time
where people were being very optimistic
that progress, the march of progress,
would go on forever until we got to some
utopian civilization. But from Thomas
Malthus' point of view, he felt that if people
could reproduce and increase the population, they
will, that there's no way of stopping them. So from his point
of view, the way he saw it-- so let
me on that axis-- let's say that that
is the population, and that this axis
right over here, let's say that that is time. So by his thinking--
and everything that he'd seen in reality
up to that point would back this up-- that if people
had enough food and time, they would reproduce,
and they would reproduce in numbers that would
grow the population. So in his mind, the population
would just keep on increasing. It'll just keep on increasing,
until it can't support itself anymore, until the actual
productivity of the land can't produce enough calories
to feed all of those people. So in his mind, there would
be some natural upper bound based on the actual
amount of food that the earth could support. So let's say that
this is-- let me do that in a different
color-- so in his mind, there was some upper
bound, and once you get to that upper
bound, then all of a sudden, the vices
of mankind will show up. And if those don't start
killing people, then all of these other things
will, epidemics, pestilence, plague, and then famine. People are actually
starving to death. So in his mind, once you
got to this level, maybe you had a couple of
good crops, people are feeling good about
themselves, they overpopulate. But then, all of a sudden,
you have a bad crop, or because you have
a bad crop, people start fighting over
resources, and wars happen. Or maybe the population is so
dense that a plague develops. And then you have a massive
wave of depopulation. And so you would just
oscillate around this limit. And this limit some people
refer to as a Malthusian limit, but it's just really
the limit at which the population can
sustain itself. And from Thomas
Malthus' point of view, he did recognize that there
were technological improvements, especially in things
like agriculture. And that this line
was moving up. He had seen it in
his own lifetime, that this line had moved up. But from his point
of view, however far you moved this
line up, the population will always compensate
for it and catch up to it, and eventually get to
these Malthusian limit. And then the same
not-so-positive things that he talks about
would actually happen. And some people now
say, oh Thomas Malthus, he was so pessimistic. He was obviously wrong. Look at what's happened. We have so much food on
this planet right now. We've gone through multiple
agricultural revolutions, and they are right. In the last 200
years, since Malthus, so since the early
1800s, we really have been able to
outstrip population. So this line up here
has been moving up much faster than
even population. So right now, we actually
do have more calories per person on the
planet than we've had at any time in history. But it's not saying that
Thomas Malthus was wrong, it's just saying that maybe
he was just a little bit pessimistic in when that
limit will be reached. Now the other
dimension where you might say that he was maybe
wrong was in this principle that a population will
increase if it can increase. If there is food, and if there
is time, people will reproduce. And a good
counterpoint to that is what we've now observed in
modern, developed nations. And so this right over here
shows the population growth. I got this from the World Bank. But the population growth of
some modern, developed nations. And you can see the United
States is pretty low, but it's still positive. It's still over half a percent. But even that adds up
when you compound it. But if you look over
here, Japan and Germany-- and Japan and Germany
have less immigration than the United States,
especially Japan-- they are actually negative. So just this population
left to its own devices, especially if you
account for people not going across borders, just
the population itself growing, they actually have
negative growth. So there's some reason to
believe that this is evidence that Thomas Malthus was wrong,
or not completely right. He didn't put into account that
maybe once a society becomes rich enough and educated
enough, that they might not just populate the world, or have
as many kids as they want, they might try to
do other things with their time,
whatever that might be. So I just wanted to
expose you to this idea. Time will tell if Thomas
Malthus, if we can always keep this line of food
productivity growing faster than the population. And time will tell whether
our populations can become, I guess we could say,
developed enough, so that they don't inex--
I can never say that word. They don't always
just keep growing. Maybe they do become a Japan
or a Germany situation. And the world
population, especially if we have a high
rate of literacy, eventually does level off. So it never even has
a chance of hitting up against that Malthusian limit. But I thought I would
introduce you to the idea, and now you can go
to parties and you can talk about things
like Malthusian limits. And if you want to know
what country is maybe closest to the Malthusian
limit right now-- and we've talked about this
before-- but a good case example is something
like Bangladesh. They are, right now, the
most population-dense country in the world. They have 900 people
per square kilometer. And just to give you a
sense of perspective, that's 30 times more dense
than the United States is. So if you took every person
in the United States, and turned them into 30
people in the United States, that would give you a sense
of how dense Bangladesh is. And it's probably due
to a certain degree that it's a very fertile land. The river delta of the
Ganges essentially makes up the entire country. But they do, they have
in the past, had famines. They've gotten a
little bit beyond that. But still, you do
have major problems with flooding and resources. So hopefully they'll be able
to stay ahead of the curve.