My view on this is rather that there seem to be several key technologies and measures of progress that have very limited room for further growth, and the ~zero-to-one growth that occurred along many of these key dimensions seems to have been low-hanging fruit that coincided with the high growth rates that we observed around the mid-1900s. And I think this counts as modest evidence against a future growth explosion.
Hmm, it seems to me like these observations are all predicted by the model I’m advocating, so I don’t see why they’re evidence against that model. (Which is why I incorrectly thought you were instead saying that there wasn’t room for much growth, sorry for the misunderstanding.)
(I do agree that declining growth rates are evidence against the model.)
At any given point in time, I expect that progress looks like “taking the low-hanging fruit”; the reason growth goes up over time anyway is because there’s a lot more effort looking for fruit as time goes on, and it turns out that effect dominates.
For example, around 0 AD you might have said “recent millennia have had much higher growth rates because of the innovations of agriculture, cities and trade, which allowed for more efficient food production and thus specialization of labor. The zero-to-one growth on these key dimensions was low-hanging fruit, so this is modest evidence against further increases in growth in the future”; that would have been been an update in the wrong direction.
At any given point in time, I expect that progress looks like “taking the low-hanging fruit”; the reason growth goes up over time anyway is because there’s a lot more effort looking for fruit as time goes on, and it turns out that effect dominates.
I think the empirical data suggests that that effect generally doesn’t dominate anymore, and that it hasn’t dominated in the economy as a whole for the last ~3 doublings. For example, US Total Factor Productivity growth has been weakly declining for several decades despite superlinear growth in the effective number of researchers.
I think the example of 0 AD is disanalogous because there wasn’t a zero-to-one growth along similarly significant and fundamental dimensions (e.g. hitting the ultimate limit in the speed of communication) followed by an unprecedented growth decline that further (weakly) supports that we’re past the inflection point, i.e. past peak growth rates.
Hmm, it seems to me like these observations are all predicted by the model I’m advocating, so I don’t see why they’re evidence against that model. (Which is why I incorrectly thought you were instead saying that there wasn’t room for much growth, sorry for the misunderstanding.)
(I do agree that declining growth rates are evidence against the model.)
At any given point in time, I expect that progress looks like “taking the low-hanging fruit”; the reason growth goes up over time anyway is because there’s a lot more effort looking for fruit as time goes on, and it turns out that effect dominates.
For example, around 0 AD you might have said “recent millennia have had much higher growth rates because of the innovations of agriculture, cities and trade, which allowed for more efficient food production and thus specialization of labor. The zero-to-one growth on these key dimensions was low-hanging fruit, so this is modest evidence against further increases in growth in the future”; that would have been been an update in the wrong direction.
I think the empirical data suggests that that effect generally doesn’t dominate anymore, and that it hasn’t dominated in the economy as a whole for the last ~3 doublings. For example, US Total Factor Productivity growth has been weakly declining for several decades despite superlinear growth in the effective number of researchers.
I think the example of 0 AD is disanalogous because there wasn’t a zero-to-one growth along similarly significant and fundamental dimensions (e.g. hitting the ultimate limit in the speed of communication) followed by an unprecedented growth decline that further (weakly) supports that we’re past the inflection point, i.e. past peak growth rates.