Prices have doubled since 1999!? Restaurant prices near me have doubled since 2015, easily. And that's not counting delivery going from free to 25% of the meal cost.

Not quite. The value of the currency has declined by 33% since 1999.

Prices are subject to the combination of the value of the currency and the value of the good. Food may be worth more than in the past, for example, so you cannot look at the value of the currency alone.

The value of the currency relative to an evolving bag of reference goods.

Value is always relative. Typically currency is what we use as the relative point of comparison, but obviously you cannot compare the value of the currency with the value of the currency. Hence why we flip things around. A bag of goods, as opposed to a single item, filters out the noise of each individual good changing in value independently.

Food is one of the things that's going to have the least change in value.

Quite the opposite. Value is essentially a function of scarcity relative to desire. Food desire may be, for all intents and purposes, stable, but availability is most certainly not. Something like a major weather event wiping out a crop can quickly change the scarcity profile. Food is especially prone to value variances over time.

Also, desire for restaurant service is driven by people with disposable income looking to treat themselves much more than baseline food prices. Restaurants serving this demand can optimise prices for their limited capacity, and have staff and real estate costs to consider

What specific definition of value are you using here? Sometimes terms with value get into the same realm as price, but the default definition of value is the benefit you're getting, and going to similar restaurants ten years apart is damn near the same benefit. Scarcity doesn't come into play.

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".

However, if we are to change gears, the benefit you get out of a restaurant isn't constant either. Aside from maybe those trying to serve the elderly population, where there seems to be a viable niche of providing "remembrance of how things were in the good old days", restaurants that try to offer constant value quickly go out of business. They are forever needing to up their game to appeal to the typical clientele. Customers want increasingly more benefit as time marches forward to justify the visit.

An individual's perception of benefit is personal, so it is true that any given individual may not find increased benefit in restaurants trying to outdo each other by offering more and more benefits, but within populations it seems quite apparent that restaurants that "win" generally are offering more benefits (higher quality/more exotic/creative food, increasingly sophisticated ambiance, etc.) than they did in the past.

> 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.

It's using a fixed value of goods and measuring the price of that basket to measure the value of a dollar.

The price of a dollar is one dollar. That's a useless statistic.

> It's using a fixed value of goods

The CPI basket is definitely not fixed. It is constantly evolving to ensure that the metric is useful. Consumption habits are not fixed.

> The price of a dollar is one dollar.

Technically true, just like the price of one iPhone is the price of one iPhone (assuming equivalent specs), but in the real world price is used to compare the value of different things. Currently, the price of an iPhone 17 Pro is 238 bushels of corn.

The basket shifts but it's trying to stay equivalent. Not in dollar terms but in benefit terms. If it's not trying to have a stable value then it's not a useful measuring stick.

Not in benefit terms, in buying habit terms. CPI tries to be calculated on a regular basis, and thus is only useful if it looks at things people are actually buying. If people used to regularly buy steak, but due to production issues there isn't much to go around, where customers have largely shifted to buying ground beef instead, then steak is no longer a useful item in the basket. It will get phased out in favour of ground beef.

Steak is objectively more valuable in the traditional sense, as evidenced by the price, and also quite arguably more valuable than ground beef in the "benefit" sense, but that doesn't matter. Ground beef is just as good in the basket as CPI only needs to see relative change in price. It is not measuring benefit.

Pick your favorite crop and look at yields per acre over the last century.

If I have to look at an entire century I think that proves my point.

I mean looking at fold change, even full order of magnitude increases is pretty interesting.

Yes restaurant prices have increased more but other things have increased less. For example entertainment, clothing, electronics, even automobiles.

Not all components rise in cost at the same time. Overall, prices have roughly doubled since the early 2000's--things that I expect to cost, say, $10 would now cost around $20. However, some things have risen in cost much more quickly: housing prices, for one.

The things you are talking about are a phenomenon largely of the COVID era and later. The biggest wage gains post-COVID have been in the lowest end of the job market, and services where almost-minimum-wage labor is a high fraction of their cost have commensurately risen in price the fastest (e.g., fast food). Similarly, a lot of the easy money flowing into unprofitable grow-then-make-money businesses (like delivery firms) have stopped flowing in, so those services have had to actually make money from customers, which causes their costs to rise.

Except for a brief spike during Covid unemployment has been below 5% for a long time which has led to more wage growth for cooks and waiters than for programmers.

It's CPI, they'll just keep changing the basket of goods until the numbers look like they want them to.

"Well, inflation since 2015 is nonexistent if you swap out steaks for 3 day old catfish and fruits for kool aid packets"