7 September 2026
We were not looking for it. We were trying to fix what looked like a bug and ran into a linguistic border that runs through the price lists.
The bug that was not a bug
To measure the price of a pita gyros we read public shop catalogues and keep the items that are wraps. The list of words meaning wrap contained the word sandwich.
That looks like an obvious oversight. Gyros in bread is a different product, bigger and dearer, and has no place in an index that counts pita wraps. We went to remove it.
Before removing it, we measured what it would do. Just as well: Thessaloniki would have fallen from 98 shops to 7. Nationally 209 of 1,113 shops would have lost their price, 19% of the sample.
In Thessaloniki the wrap is called a sandwich
The reason has nothing to do with the product: 91 of the city's 98 shops with a named item price from something called a sandwich. The word pita barely appears in their catalogues.
Nor is it one city's quirk. In 12 cities sandwich is the majority name: Serres 100%, Giannitsa 100%, Thessaloniki 93%, Veria 91%, Katerini 83%, Halkidiki 80%, Kastoria 75%, Larisa 73%, Florina 71%, Alexandroupoli 56%, Kavala 53%, Xanthi 50%. At the other end, in 30 cities with four shops or more not a single shop uses it, not once.
On the map the border shows at once, and it is narrower than simply the north: the twelve are Macedonia, Thrace and Thessaly. Ioannina, Igoumenitsa, Arta and Corfu are just as northern and sit at ZERO. The word stops at the Pindus range rather than simply spreading down from the border.
How we know it is the same thing
The name alone proves nothing. The north could genuinely be eating gyros in bread, in which case we would be measuring a different product and calling it a pita wrap.
Price answers the question. In the cities where sandwich dominates but both words appear, the median ratio between them is 1.024. In Katerini they are exactly equal, 4.00 € each. In Kastoria 3.90 € for the pita and 3.80 € for the sandwich.
Note what is being compared: not two items inside one shop, but the median of the shops that call it a pita against those that call it a sandwich, within the same city. Two names at the same price in the same market mean one product. If one were the large bread sandwich, it would cost more.
And in the south the same word means something else
This is where it gets interesting. In cities where the word is rare, the few sandwiches that exist really are a different and dearer product: Lefkada 7.00 € against 4.80 €, Heraklion 6.00 € against 4.90 €, Ioannina 5.60 € against 4.20 €, Athens 6.80 € against 4.20 €.
So the same word means the ordinary wrap in the north and gyros in bread in the south. They are neither synonyms nor homonyms, they are both, depending on where you stand.
In Athens, of 445 shops with a named item, exactly three price from a sandwich. The map does show one southern exception, Argos, but on two shops out of five: far too small a sample to mean anything, and we are not claiming it does.
Why it matters for measurement
An index that reads catalogues mechanically cannot see the difference. It sees a word and decides. When it decides wrongly, nothing turns red: it produces a number that looks reasonable.
What keeps the two apart is that we always take the cheapest matching item in a shop. In Athens, where a shop has both a pita and a sandwich, the pita wins. In Thessaloniki there is no pita to win, so we take the sandwich, which is the right answer.
It is written down and pinned by an automated test, so that whoever next sees the word in the list and wants to tidy the code up learns first what it would break.
See the same numbers live in the interactive dashboard.
The figures in this article are not written by hand: they are computed from the data series and change when it does. Prices and wages up to August 2026. Dataset version 2026.09-pita-i-santouits, last updated 2026-09-07.