It’s possible that resource constraints are a bottleneck, and this is an important area for further research, but our guess is that they won’t be. Historically, resource bottlenecks have never capped GDP growth – they’ve been circumvented through a combination of efficiency improvements, resource substitutions, and improved mining capabilities.
Well, most of human history was spent at the malthusian limit. With infinite high-quality land to expand into, we’d probably have been growing at much, much faster rates through human history.
(It’s actually kind of confusing. Maybe all animals would’ve evolved to exponentially blow up as fast as possible? Maybe humans would never have evolved because our reproduction is simply too slow? It’s actually kind of hard to design a situation where you never have to fight for land, given that spatial expansion is at most square or cubic, which is slower than the exponential rate at which reproduction could happen.)
Maybe you mean “resource limits have never put a hard cap on GDP”, which seems true. Though this seems kind of like a fully general argument — nothing has ever put a hard cap on GDP, since it’s still growing.
Edit: Hm, maybe historical land constraints at the malthusian limit has mostly been about energy, though, rather than raw materials? Ie: If you doubled Earth’s size without doubling any valuable materials — just allowing Earth to absorb more sunlight, maybe that would be almost as good as doubling Earth in its entirety. That seems more plausible. Surely growth would’ve been at least a bit faster if we never run out of high-quality sources of any raw material, but I’m not sure how much of a difference it would make.
It’s a bit of a confusing comparison to make. If we doubled Earth’s area (and not resources) now, that would scarcely make a difference at all, but if it had been twice as large for millions of years, then maybe plants and animal life would’ve spread to the initially-empty spaces, making it potentially useable.
I believe I was here thinking about how society has, at least in the past few hundred years, spent a minority of GDP on obtaining new raw materials. Which suggests that access to such materials wasn’t a significant bottleneck on expansion.
So it’s a stronger claim that “hard cap”. I think a hard cap would, theoretically, result in all GDP being used to unblock the bottleneck, as there’s no other way to increase GDP. I think you could quantify the strength of the bottleneck as the marginal elasticity of GDP to additional raw materials. In a task-based model, i think the % of GDP spent on each task is proportional to this elasticity?
Though this seems kind of like a fully general argument
Yeah, I think maybe it is? I do feel like, given the very long history of sustained growth, it’s on the sceptic to explain why their proposed bottleneck will kick in with explosive growth but not before. So you could state my argument as: raw materials never bottlenecked growth before; no particular reason they would just bc growth is faster bc that faster growth is driven by having more labour+capital which can be used for gathering more resources; so we shouldn’t expect raw materials to bottleneck growth in the future.
TBC, this is all compatible with “if we had way more raw materials then this would boost output”. E.g. in Cobb Douglas doubling an input to output increases output notably, but there still aren’t bottlenecks.
(And i actually agree that it’s more like CES with rho<0, i.e. raw materials is a stronger bottleneck, but just think we’ll be able to spend output to get more raw materials.)
(Also, to clarify: this is all about the feasibility of explosive growth. I’m not claiming it would be good to do any of this!)
I do feel like, given the very long history of sustained growth, it’s on the sceptic to explain why their proposed bottleneck will kick in with explosive growth but not before. So you could state my argument as: raw materials never bottlenecked growth before; no particular reason they would just bc growth is faster bc that faster growth is driven by having more labour+capital which can be used for gathering more resources; so we shouldn’t expect raw materials to bottleneck growth in the future.
Gotcha. I think the main thing that’s missing from this sort of argument (for me to be happy with it) is some quantification of our evidence. Growth since 10k years ago has been 4-5 OOMs, I think, and if you’re just counting since the industrial revolution maybe it’s going to be a bit more than half of that.
So with that kind of outside view, it would indeed be surprising if we ran into resource bottlenecks in our next OOM of growth, and <50% (but not particularly surprising) if we ran into resource bottlenecks in the next 3 OOMs of growth.
(I think epoch’s paper on this takes a different approach and suggests an outside view of hyperbolic growth lasting for ~1.5y OOMs without bottlenecks, because that was the amount grown between the agricultural evolution and the population bottleneck starting. That feels weaker to me than looking at more specific hypotheses of bottlenecks, and I do think epoch’s overall view is that it’ll likely be more than 1.5 OOMs. But wanted to flag it as another option for an outside view estimate.)
Well, most of human history was spent at the malthusian limit. With infinite high-quality land to expand into, we’d probably have been growing at much, much faster rates through human history.
(It’s actually kind of confusing. Maybe all animals would’ve evolved to exponentially blow up as fast as possible? Maybe humans would never have evolved because our reproduction is simply too slow? It’s actually kind of hard to design a situation where you never have to fight for land, given that spatial expansion is at most square or cubic, which is slower than the exponential rate at which reproduction could happen.)
Maybe you mean “resource limits have never put a hard cap on GDP”, which seems true. Though this seems kind of like a fully general argument — nothing has ever put a hard cap on GDP, since it’s still growing.
Edit: Hm, maybe historical land constraints at the malthusian limit has mostly been about energy, though, rather than raw materials? Ie: If you doubled Earth’s size without doubling any valuable materials — just allowing Earth to absorb more sunlight, maybe that would be almost as good as doubling Earth in its entirety. That seems more plausible. Surely growth would’ve been at least a bit faster if we never run out of high-quality sources of any raw material, but I’m not sure how much of a difference it would make.
It’s a bit of a confusing comparison to make. If we doubled Earth’s area (and not resources) now, that would scarcely make a difference at all, but if it had been twice as large for millions of years, then maybe plants and animal life would’ve spread to the initially-empty spaces, making it potentially useable.
Thanks! (Quickly written reply!)
I believe I was here thinking about how society has, at least in the past few hundred years, spent a minority of GDP on obtaining new raw materials. Which suggests that access to such materials wasn’t a significant bottleneck on expansion.
So it’s a stronger claim that “hard cap”. I think a hard cap would, theoretically, result in all GDP being used to unblock the bottleneck, as there’s no other way to increase GDP. I think you could quantify the strength of the bottleneck as the marginal elasticity of GDP to additional raw materials. In a task-based model, i think the % of GDP spent on each task is proportional to this elasticity?
Yeah, I think maybe it is? I do feel like, given the very long history of sustained growth, it’s on the sceptic to explain why their proposed bottleneck will kick in with explosive growth but not before. So you could state my argument as: raw materials never bottlenecked growth before; no particular reason they would just bc growth is faster bc that faster growth is driven by having more labour+capital which can be used for gathering more resources; so we shouldn’t expect raw materials to bottleneck growth in the future.
TBC, this is all compatible with “if we had way more raw materials then this would boost output”. E.g. in Cobb Douglas doubling an input to output increases output notably, but there still aren’t bottlenecks.
(And i actually agree that it’s more like CES with rho<0, i.e. raw materials is a stronger bottleneck, but just think we’ll be able to spend output to get more raw materials.)
(Also, to clarify: this is all about the feasibility of explosive growth. I’m not claiming it would be good to do any of this!)
Gotcha. I think the main thing that’s missing from this sort of argument (for me to be happy with it) is some quantification of our evidence. Growth since 10k years ago has been 4-5 OOMs, I think, and if you’re just counting since the industrial revolution maybe it’s going to be a bit more than half of that.
So with that kind of outside view, it would indeed be surprising if we ran into resource bottlenecks in our next OOM of growth, and <50% (but not particularly surprising) if we ran into resource bottlenecks in the next 3 OOMs of growth.
(I think epoch’s paper on this takes a different approach and suggests an outside view of hyperbolic growth lasting for ~1.5y OOMs without bottlenecks, because that was the amount grown between the agricultural evolution and the population bottleneck starting. That feels weaker to me than looking at more specific hypotheses of bottlenecks, and I do think epoch’s overall view is that it’ll likely be more than 1.5 OOMs. But wanted to flag it as another option for an outside view estimate.)