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.)
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.)