You still misread the article: they observe the nearly constant 2% growth across the long timespan, regardless of the relative increases in researchers, regardless of all the policy changes, regardless of ...
The article is NOT about some recent change. Please cite the article if you believe it is trying to solve a puzzle concerning a recent change.
The whole point is that this 2% seems to be robust, regardless of investing or getting more ideas, invalidating the idea that the growth is a simple result of the production of ideas (say making blueprints for a new kind of factory, which can then be copied without having to make more blueprints).
I am not asking you for a random citation of the article, but one that demonstrates the article discusses a puzzle concerning a recent trend, as opposed to a longtime ongoing one.
Your citation of the article:
> This is a puzzle! Why would the market fail to reward innovative firms, or, conversely, why does it continue rewarding less innovative firms? Unfortunately, here we don’t have clear answers.
does not refer to any recent change, indeed, it uses the word "continue" invalidating your claim that the puzzle is about some recent change.
The article is NOT about some recent change. Please cite the article if you believe it is trying to solve a puzzle concerning a recent change.
The whole point is that this 2% seems to be robust, regardless of investing or getting more ideas, invalidating the idea that the growth is a simple result of the production of ideas (say making blueprints for a new kind of factory, which can then be copied without having to make more blueprints).