It seems to me that there are two types of simplification:
Simplification for pedagogical purposes (e.g. “imagine this as a point mass moving on a frictionless plane…”)
Simplification for no good reason (e.g. “balls rolling on a surface will eventually stop because of their natural motion”)
I agree that overhead ratios are simplification of the second form: they are not much more complex than things like QALY/dollar yet are much less informative.
I disagree though that QALY/dollar is pointless simplification. It is definitely the case that we need to consider flow-through effects, how are decisions affect the unborn etc., but for both practical as well as pedagogical reasons we might say something like “let us suppose that we only care about human beings living right now.” This seems very analogous to a physicist talking about point masses or an economist talking about perfect competition.
I’m curious if you disagree that these simplifications are useful? Or do you just think we should do a better job of calling out that they are simplifications?
Thanks for the interesting post!
It seems to me that there are two types of simplification:
Simplification for pedagogical purposes (e.g. “imagine this as a point mass moving on a frictionless plane…”)
Simplification for no good reason (e.g. “balls rolling on a surface will eventually stop because of their natural motion”)
I agree that overhead ratios are simplification of the second form: they are not much more complex than things like QALY/dollar yet are much less informative.
I disagree though that QALY/dollar is pointless simplification. It is definitely the case that we need to consider flow-through effects, how are decisions affect the unborn etc., but for both practical as well as pedagogical reasons we might say something like “let us suppose that we only care about human beings living right now.” This seems very analogous to a physicist talking about point masses or an economist talking about perfect competition.
I’m curious if you disagree that these simplifications are useful? Or do you just think we should do a better job of calling out that they are simplifications?