[This is part of my series on Thomas Malthus’ “Essay on the Principle of Population,” first published in 1798. You can find an overview of all posts here that I will keep updated: “Synopsis: What’s Wrong with the Malthusian Argument?”]
I have come across this today. It is a tweet from the renowned development economist William Easterly. He comments on this graph:
And that’s what he writes:
World population since 10,000 BC: not much happened until very recently. Six and a half percent of all people who were ever born over the last 12,000 years are alive today.
I have not done the math, but I assume that the claim in the second sentence is correct, and that is perhaps baffling. My quibble is with the first claim that “not much happened until very recently.”
The point I am trying to make here is broader than it may seem. My contention is that the Malthusian argument has had no merit from the start. But it comes with an associated worldview that has had a major impact on how we see the world. This is part of our culture.
And that means that even people who are not Malthusians in a narrow sense — that’s what I assume for Easterly — will take certain assumptions for granted. One of them is that “not much happened until very recently.” World history until perhaps 1800 or some other similar cut-off was one long stagnation. Then something extraordinary happened that messed Thomas Malthus’ theory up.
But that is not true.
And it is easy to show this. Population estimates for 1800 fall in a range from 890 million to one billion (I take the data from this Wikipedia page, the exact numbers are not essential here or the cut-off date because you can drive a truck through.) Eyeballing the graph, the estimate for 2100 appears to be something like 11 billion. I am skeptical about such projections, but I will just accept this one for the time being. So, the whole increase over three centuries is roughly by a factor of 11 or 12.
Now take estimates for the size of humankind in -10,000 BC, which are rather imprecise. The range is from one to ten million people (cf. the same source). This is an increase until 1800 by a factor of roughly 89 (10m > 890m) or even 1,000 (1m > 1b). And that is a much larger increase than what happens at the end of the graph.
Of course, this boost worked out much more slowly. But then this does not take anything away from the fact that it was far more massive. And true, it was also less in absolute numbers because the base level in 1800 was already one billion or somewhat less and so an increase by a factor will lead to a much larger number than with one or ten million people.
But then “not much” makes only sense for relative changes. Take this as an example: Mali has currently very high population growth of about 2.7% annually, but only a population of some 18 million people. So this works out to only an addition of about 770,000 people. China has a population of 1.4 billion people, but much slower population growth of only 0.59%. Hence the absolute increase is by about 8.2 million people, more than ten times that for Mali. Still, it would seem absurd to claim that “not much happens” in Mali.
Estimates for the original population that we are all descended from perhaps 100,000 years ago are for 100,000 to 300,000 people. So you could multiply the factor before 1800 with a range from 89 to 1000 by another factor of about 3.3 (300K > 1m) or even 100 (100K > 10m), which gives a range from about 3,000 (300K > 1m > 890m) to 10,000 (100K > 10m > 1b). Quite to the contrary, almost everything that has happened with humankind happened before 1800, not afterwards.
But if you are under the influence of the Malthusian worldview, you can look at the above graph as if it really showed that “not much happened until very recently.” I don’t fault anyone for this, not William Easterly either. It is simply so intriguing if you already know this from the Malthusian worldview and you get the easy confirmation by looking at a graph where the main part is not visible because the scale shrinks it almost to a flat-line.
Just to repeat the point and to hammer it in against our Malthusian worldviews: Almost everything that happened with humankind came before 1800, the rest is not remarkable by comparison, only perhaps its speed.
PS: Sorry, messed the figures up at first, hope I get it right now. But then the argument is as I said so safe you can drive a truck through.