It was never proven wrong, as much as the world changed in a way that invalidated it.
The entire idea was that population growth was an exponential function, whereas agriculture output was a linear function. There would have been famine if nothing had changed, because there is only a certain amount of physical labor a person is capable of doing, which has to be divided between the farming, logistics, and cooking of the food.
What happened was that a century later we got mechanized farming and synthetic fertilizer, decoupling agricultural output from the population. Now a single person can do the work of thousands, and every year that number grows due to technology advances. It is too expensive to set up fully automated farms on the industrial scale, but it is technologically possible.
But none of that invalidates his idea. If you believe that an exponential function and linear function sharing a point at (0,0) must cross each other (subject to other reasonable conditions like not having crossed yet, the linear having a positive finite slope, etc), then it is not logical to reject Malthus. It just no longer applies because we decoupled our food production capacity from the population size.
You also have to believe that population growth is fully exponential. But in practice it looks more like a logistic curve, and the factors that slow it down are a lot less dramatic than resource starvation or violence.
You do not have to believe population growth is fully exponential for it to be a valid conclusion. You just have to have human population grow faster than agricultural capacity, which it was.
Additionally, it is reasonable in the 1790s to assume exponential population growth. It would not be until the 1830s that Verhulst would even model it as a logistic curve. Moreover, human population growth really was on a roughly exponential trajectory until very recently.
Obviously we did not experience such catastrophe. But it's also a bit wrong to call it "invalid" when it was a completely logical conclusion to make. If we're going to allow him to invent a magical technology that addresses it in 1798, then all reason goes out the window.
As long as I keep hearing about the need for reducing meat consumption and supply chain slack (food waste), I'm inclined to think Malthus was right despite the limit turning out to be soil capacity rather than labour capacity.
And because of this, many will starve as a result of oil shocks from the disruption and chaos in the gulf region. We solved the trolley problem by throwing a magic lever that puts five descendants of the original person a ways down the tracks.
I mean insofar as the idea is about contemplating those mechanisms in the abstract, sure. But insofar as they were predictive or an attempt at a descriptive characterization of where populations would actually go, clearly it didn't hold. And if it didn't hold because it's true on it's own terms in some abstract sense, so much the worse for its inability to model changes that would prove to be relevant to actual population dynamics.
It's also not just that we accommodated explosive populations but that eventually birth rates really did simply start slowing down for discernible reasons that future models were capable of integrating. Even if we continue to have technology that would give us the capacity to accommodate future increases in population, those increases are no longer happening.
> And if it didn't hold because it's true on it's own terms in some abstract sense, so much the worse for its inability to model changes that would prove to be relevant to actual population dynamics.
That's a bit unfair to Malthus though; sure it was the enlightenment, but all he could rationally go on was to assume that the last 2000 or so years of civilization would be similar to the next, in terms of food and population growth.
What would be abstract would be to make the assumption that unprecedented technological advancement would be made in the next hundred years, bordering on ( to what Malthus would be) magic. You can assume any problem will be solved if you also assume a technology will be invented to fix it. But that's not a reasonable approach to make if you have no reason to believe it is possible.
I agree he wasn't able to anticipate technological changes or the impact they would have, but the response to that isn't to simply insist his theory is literally still true just because he tried his best. I'm not suggesting he could or should have done that, but I don't have to have that expectation to nevertheless note, correctly, that it's not a model of the population dynamics we actually see.
I mean, by proven wrong that's what I mean. I'm not talking about the theoretical mathematics but the real world application of theory in which case, yes, Malthus was proven wrong.
I wouldn't say proven or disproven, as much as it became no longer applicable.
The world he was modeling in the 18th century is a very different world than we ended up getting. IMO it's neither right nor wrong, it's just a reasonable observation that made sense for the time.
It's somewhat analogous to Y2K, in that there were obvious problems that were going to happen. We didn't experience those negative outcomes because immense engineering effort solved the underlying problem. That doesn't mean Y2K was "invalid" or "wrong," just that the problem itself got addressed before it could blow up. Same with Malthus, chemistry and mechanization allowed us to solve the underlying issue of food production scaling slower than population growth.
He was proven wrong in that what he predicted didn't happen. That's wrong enough to be called "wrong", no matter how reasonable his reasoning was at the time.
And you missed one point with your discussion of linear and exponential. Agriculture wasn't linear. It wasn't even in his day. There was improvement in per-person output since, say, the 1400s, and more since, say, 2000 BC. There was a technological component even then.
So population wasn't exponential, agriculture wasn't linear, and what he said would happen didn't happen. How much more wrong does he have to be before you are willing to call him "wrong"?
> He was proven wrong in that what he predicted didn't happen.
Not really my point. Malthus was wrong about a future food crisis, but that doesn't invalidate the tools he used to make that prediction. Re-read the first line of my original post, it's pretty clearly about the theory and not his predictions.
The underlying idea is that population growth outpaced food production, and we know it is bad for food consumption exceed production.
> And you missed one point with your discussion of linear and exponential
You're also missing the forest for the trees: agriculture and population growth can be any two functions for the idea to work, so long as the agriculture function starts higher than the population function (technically there is a third function implicitly here connecting population growth to food consumption) and grows slower. Population growth was approximately exponential, and food production was approximately linear. This is a sufficient condition to forecast future changes. Pick any overfit function you'd like for food or population as it was known to Europe in the 1790s, and you will arrive to the same conclusion if you do not "cheat" and allow for magical technology advances in 50 years.
> How much more wrong does he have to be before you are willing to call him "wrong"?
Math would have to change to the point that subtracting consumption from production no longer leads to a negative number for me to consider him "wrong."
Now, I wouldn't say his model was relevant to famine after technology changed, because it no longer was useful for that particular thing. But the core notion of "if demand grows faster than supply, you will eventually hit a crisis when they intercept" is a pretty clear-cut conclusion to draw.
It is a bit odd for a thread to get this heated over a pretty simple economic theory that stopped being relevant a century ago. Is there some political side to Malthus I am missing?
It was never proven wrong, as much as the world changed in a way that invalidated it.
The entire idea was that population growth was an exponential function, whereas agriculture output was a linear function. There would have been famine if nothing had changed, because there is only a certain amount of physical labor a person is capable of doing, which has to be divided between the farming, logistics, and cooking of the food.
What happened was that a century later we got mechanized farming and synthetic fertilizer, decoupling agricultural output from the population. Now a single person can do the work of thousands, and every year that number grows due to technology advances. It is too expensive to set up fully automated farms on the industrial scale, but it is technologically possible.
But none of that invalidates his idea. If you believe that an exponential function and linear function sharing a point at (0,0) must cross each other (subject to other reasonable conditions like not having crossed yet, the linear having a positive finite slope, etc), then it is not logical to reject Malthus. It just no longer applies because we decoupled our food production capacity from the population size.