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.
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.