This sequence was incredibly interesting while also being very short and to the point. Thanks a great deal for writing it.
Generally speaking i think your hypothesis is interesting and plausible.
A few questions
For the narrow vs wide glass metaphor for population, does it really line up with the multi-century timelines involved? If populations can grow 2x every 20 years in these societies, wouldn’t europe have filled up with people much faster? Isn’t the fact that it didn’t down to a lack of technology (complex agriculture and settled states able to defend agriculture)?
How much evidence is there that concrete production fell due to lack of fuel as opposed to, say, economic collapse and constant civil wars drastically reducing demand for very expensive high-grade building materials?
Your model of intensive agriculture seems to be “everyone knows what it is but people won’t do it until it’s necessary”. Is this true? Isn’t intensive agri a super advanced tech which took centuries to develop and diffuse? Isn’t every pre-industrial society pretty much permanently at the malthusian limit, meaning everyone would already have an incentive to do intensive agriculture if possible.
Do you think the greeks developed so quickly because they were land bound and hence had to resort to intensive agriculture? Why not other hypothesis like them being next to the sea = hugely more mobility + trade = hugely more wealth = higher pop densities and more specialization in complex good creation.
In regards to your last point: I’ll certainly concede that naval mobility must have been very helpful to the Greeks. As a Dutch person, I’m well aware how helpful sea-based trade was, historically :)
In regards to the third point: are you aware that early farmers were shorter and had significantly worse health than hunter-gatherers? I don’t believe it was an amazing new invention, it’s a thing desperate, hungry people do when ‘wild’ food resources run out. It allowed for sedentary life and higher population densities, and in the very long term that’s crucial for ‘civilization’, but it was not an improvement for the individual.
I believe that trade-off didn’t happen merely at the start, when the first hunter-gatherers switched to agriculture, I believe that trade-off to have increased gradually as agriculture became more intensive.
I’m going to be deeply unfair here and it’s easy to criticize these emotional arguments, but look at this drawing of a Bronze Age farm versus Victorian London homes, at the start of the Industrial Revolution. Victorian England had way more advanced technology, and as an empire, it had very impressive stats. But I doubt I wanted to live there as a middle-class or poor individual. (Not saying the Bronze Age was awesome, but day-to-day life may have been more tolerable).
I think Ancient Egypt must have been similarly terrible for individuals. Long hours of hard physical farm labor in dense, crowded villages. It creates mighty nations, but I doubt it was good for individual well-being. Consider Zvi’s writings on slack.
Make sure that under normal conditions you have Slack. Value it. Guard it. Spend it only when Worth It. If you lose it, fight to get it back. This provides motivation for fighting things Out To Get You, lest you let them eat your Slack.
I believe our ancestors were human beings just like you and I. They valued slack as well. And they guarded it as well. There is a lot you can do to optimize crop yield. They weren’t desperate for technology and knowledge, they were desperate for time and energy. They didn’t plough and do all the other requirements of the most intensive agriculture unless absolutely forced to by necessity—by population pressure and land scarcity.
Think of COVID. (Disclaimer: The Netherlands has sky-high infections, overwhelmed ICs and a relatively low amount of vaccinations) We act like we’re doing ‘our best’, like we really care, and like we really want to end this pandemic. But we don’t. 99% of infected people survive, only the elderly have a serious chance of dying, so a lot of people act like it’s pretty much a flu and are not going to put their lives on hold for that.
I’m 100% certain that if away more deadly disease entered the Netherlands, we suddenly were able to take more drastic measures and actually stop that virus in its tracks. Which means we currently are not doing our best at fighting the pandemic according to our full pandemic-fighting potential, we are doing our best according to “we consider this to be a very serious flu”-potential.
I don’t think our ancestors were 24⁄7 operating on their actual this is our crop yield if we put all our effort in it potential. They were guarding their slack and trying to enjoy their lives, and they were not using all potential agricultural technology and knowledge. Ester Boserup has countless examples of this. German colonists in Argentina quickly dropped their intensive agriculture because they weren’t so land-constrained there. Sparsely populated Indonesian islands had extensive contact with other densely populated islands without adopting their agricultural technology, only doing so when their own population grew.
In regards to your first point: consider the text above. I don’t believe humans tried to optimize for population density, because it decreased their quality of life. I agree that Europe could have been become a lot denser, a lot quicker if people were rationally aiming for that, but they weren’t.
Sure, if it was just concrete that disappeared, I could believe that. But simultaneously, nearly all fuel-intensive luxuries disappear. And a lot of them, including concrete, suddenly reappear when new cheap fuel sources become available. That makes it really plausible to me that fuel is indeed the crucial element.
So I think that the explanations for the gradual spread of ever more intense agriculture are:
The population growth explanation: people gradually adopted more intense agriculture because population density rose, meaning they had to or they would starve.
The technological diffusion model: intensive agriculture was highly complex and non-obvious. The tech for it was developed in a few places and then gradually diffused. The causal link between pop and intensive agriculture is that intensive agriculture caused higher, more concentrated populations rather than being caused by it.
Why do I tend towards the latter hypothesis? A few reasons:
In pre-modern civilizations, population growth is exponential or at least very rapid. This means that if it indeed was pop density growth driving agriculture, we would expect to see far rapider adoption of it in, say, non costal europe where it took close to a thousand years after the greeks had it.
Related to the above, most pre modern societies were at the malthusian limit due to unrestrained population growth. Famines were common and starvation was a real risk most people would face multiple times in their lives. Hence I don’t think people in these societies lacked an incentive to grow more food more efficiently, even if doing so was hard. I think they just couldn’t.
This sequence was incredibly interesting while also being very short and to the point. Thanks a great deal for writing it.
Generally speaking i think your hypothesis is interesting and plausible.
A few questions
For the narrow vs wide glass metaphor for population, does it really line up with the multi-century timelines involved? If populations can grow 2x every 20 years in these societies, wouldn’t europe have filled up with people much faster? Isn’t the fact that it didn’t down to a lack of technology (complex agriculture and settled states able to defend agriculture)?
How much evidence is there that concrete production fell due to lack of fuel as opposed to, say, economic collapse and constant civil wars drastically reducing demand for very expensive high-grade building materials?
Your model of intensive agriculture seems to be “everyone knows what it is but people won’t do it until it’s necessary”. Is this true? Isn’t intensive agri a super advanced tech which took centuries to develop and diffuse? Isn’t every pre-industrial society pretty much permanently at the malthusian limit, meaning everyone would already have an incentive to do intensive agriculture if possible.
Do you think the greeks developed so quickly because they were land bound and hence had to resort to intensive agriculture? Why not other hypothesis like them being next to the sea = hugely more mobility + trade = hugely more wealth = higher pop densities and more specialization in complex good creation.
Thanks a lot!
In regards to your last point: I’ll certainly concede that naval mobility must have been very helpful to the Greeks. As a Dutch person, I’m well aware how helpful sea-based trade was, historically :)
In regards to the third point: are you aware that early farmers were shorter and had significantly worse health than hunter-gatherers? I don’t believe it was an amazing new invention, it’s a thing desperate, hungry people do when ‘wild’ food resources run out. It allowed for sedentary life and higher population densities, and in the very long term that’s crucial for ‘civilization’, but it was not an improvement for the individual.
I believe that trade-off didn’t happen merely at the start, when the first hunter-gatherers switched to agriculture, I believe that trade-off to have increased gradually as agriculture became more intensive.
I’m going to be deeply unfair here and it’s easy to criticize these emotional arguments, but look at this drawing of a Bronze Age farm versus Victorian London homes, at the start of the Industrial Revolution. Victorian England had way more advanced technology, and as an empire, it had very impressive stats. But I doubt I wanted to live there as a middle-class or poor individual. (Not saying the Bronze Age was awesome, but day-to-day life may have been more tolerable).
I think Ancient Egypt must have been similarly terrible for individuals. Long hours of hard physical farm labor in dense, crowded villages. It creates mighty nations, but I doubt it was good for individual well-being. Consider Zvi’s writings on slack.
Make sure that under normal conditions you have Slack. Value it. Guard it. Spend it only when Worth It. If you lose it, fight to get it back. This provides motivation for fighting things Out To Get You, lest you let them eat your Slack.
I believe our ancestors were human beings just like you and I. They valued slack as well. And they guarded it as well. There is a lot you can do to optimize crop yield. They weren’t desperate for technology and knowledge, they were desperate for time and energy. They didn’t plough and do all the other requirements of the most intensive agriculture unless absolutely forced to by necessity—by population pressure and land scarcity.
Think of COVID. (Disclaimer: The Netherlands has sky-high infections, overwhelmed ICs and a relatively low amount of vaccinations) We act like we’re doing ‘our best’, like we really care, and like we really want to end this pandemic. But we don’t. 99% of infected people survive, only the elderly have a serious chance of dying, so a lot of people act like it’s pretty much a flu and are not going to put their lives on hold for that.
I’m 100% certain that if a way more deadly disease entered the Netherlands, we suddenly were able to take more drastic measures and actually stop that virus in its tracks. Which means we currently are not doing our best at fighting the pandemic according to our full pandemic-fighting potential, we are doing our best according to “we consider this to be a very serious flu”-potential.
I don’t think our ancestors were 24⁄7 operating on their actual this is our crop yield if we put all our effort in it potential. They were guarding their slack and trying to enjoy their lives, and they were not using all potential agricultural technology and knowledge. Ester Boserup has countless examples of this. German colonists in Argentina quickly dropped their intensive agriculture because they weren’t so land-constrained there. Sparsely populated Indonesian islands had extensive contact with other densely populated islands without adopting their agricultural technology, only doing so when their own population grew.
In regards to your first point: consider the text above. I don’t believe humans tried to optimize for population density, because it decreased their quality of life. I agree that Europe could have been become a lot denser, a lot quicker if people were rationally aiming for that, but they weren’t.
Sure, if it was just concrete that disappeared, I could believe that. But simultaneously, nearly all fuel-intensive luxuries disappear. And a lot of them, including concrete, suddenly reappear when new cheap fuel sources become available. That makes it really plausible to me that fuel is indeed the crucial element.
So I think that the explanations for the gradual spread of ever more intense agriculture are:
The population growth explanation: people gradually adopted more intense agriculture because population density rose, meaning they had to or they would starve.
The technological diffusion model: intensive agriculture was highly complex and non-obvious. The tech for it was developed in a few places and then gradually diffused. The causal link between pop and intensive agriculture is that intensive agriculture caused higher, more concentrated populations rather than being caused by it.
Why do I tend towards the latter hypothesis? A few reasons:
In pre-modern civilizations, population growth is exponential or at least very rapid. This means that if it indeed was pop density growth driving agriculture, we would expect to see far rapider adoption of it in, say, non costal europe where it took close to a thousand years after the greeks had it.
Related to the above, most pre modern societies were at the malthusian limit due to unrestrained population growth. Famines were common and starvation was a real risk most people would face multiple times in their lives. Hence I don’t think people in these societies lacked an incentive to grow more food more efficiently, even if doing so was hard. I think they just couldn’t.