As far as I can tell, epistemic and instrumental rationality are two related Arts, even to EY, but are both under the banner of "Rationality" because they both work towards the same goal, that of optimal thinking (I can't cite any specific examples right now, but I'll throw it out there anyway).
Also, another reason for the comparative inefficiency of x-rationality could be lack of information. Epistemic rationality is the Art of filtering/modifying information for greater accuracy. Instrumental rationality is the Art of using all available information to maximize your values. So both techniques increase the amount of benefit you gain from information. But when you don't know all that much, the fine-tuning... (read more)
As far as I can tell, epistemic and instrumental rationality are two related Arts, even to EY, but are both under the banner of "Rationality" because they both work towards the same goal, that of optimal thinking (I can't cite any specific examples right now, but I'll throw it out there anyway).
Also, another reason for the comparative inefficiency of x-rationality could be lack of information. Epistemic rationality is the Art of filtering/modifying information for greater accuracy. Instrumental rationality is the Art of using all available information to maximize your values. So both techniques increase the amount of benefit you gain from information. But when you don't know all that much, the fine-tuning... (read more)