[wraptile]

> If you run out of 50% coupons to your local pizza joint, did they double their prices?

Yes. Did they double their msrp? no. They did double their effective price relative to me which is all that matters unless you're doing economic math or something.

[barrell]

The original comment was used as proof of a trend that vendors are raising prices. Would running out of coupons indicate a trend in rising pizza prices?

[wraptile]

It depends whether it's me personally who's running out of coupons or the entire supply of coupons is being reduced. If my ability to get the product for the same price is diminished then the price is being effectively raised.

In this case I'd agree that pricing is effectively raised as 10$ > 10$ - 50%, there's no need to complicate it. However this is not even the right metric for this problem, a better one would be total spent / work produced. If all customers spend more money for the same amount of work (adjusted to progress) then clearly the price is increasing. This would be true in this example as well.