I agree that making direct comparisons don’t make sense on their own merits; I used them as stand-ins for the previous period of American growth (which may be in the book, but were not in the link). I don’t think the frontier-vs-catch-up distinction matters to the point argued in the post, though: I strongly expect the American technical frontier 1920-1970 period looks more like the China or India catch-up 1970-2020 period than it does the American technical frontier 1970-2020.
Phrased another way, the time-price method gives us the same stagnation story as the conventional methods do. This is a separate question than what is to be done to speed up frontier progress.
The tweet summary from Philippon is very interesting—I just pulled it from NBER, where the title appears to be Additive Growth.
I agree that making direct comparisons don’t make sense on their own merits; I used them as stand-ins for the previous period of American growth (which may be in the book, but were not in the link). I don’t think the frontier-vs-catch-up distinction matters to the point argued in the post, though: I strongly expect the American technical frontier 1920-1970 period looks more like the China or India catch-up 1970-2020 period than it does the American technical frontier 1970-2020.
Phrased another way, the time-price method gives us the same stagnation story as the conventional methods do. This is a separate question than what is to be done to speed up frontier progress.
The tweet summary from Philippon is very interesting—I just pulled it from NBER, where the title appears to be Additive Growth.