alt Hacker News> Given that we're specifically talking about value in the context of currency and how that pertains to CPI, I am not sure where "benefit you're getting" would apply. CPI is definitely not interested in "the benefit you got".
...yes it is? It's seeing how many dollars you need for some specific goods.
> the benefit you get out of a restaurant isn't constant either
It's not exactly constant but it's pretty close. Especially over a single decade. And we can assume here that people are going to similar restaurants.
No...? Price is what we use to "see how many dollars you need for some specific good".
To be sure, the P in CPI stands for price, but that doesn't mean it is the same thing as price. The C and I are also there to indicate that it is something else.