In 5 steps: how the index works

Glossary: what each term means

Pita-Gyro Index

How many classic wraps the net minimum wage buys in one month. Wage divided by the price rescaled to today's classic wrap - not by the raw price of the era, which would make every year measure a different product.

CPI (inflation)

The Consumer Price Index measures price changes in a basket of goods and services. The catering CPI covers food-service activities; its path can differ from the general index.

Nominal vs real

Nominal is the number as printed. Real is the same number translated into today's purchasing power.

Price control

A state-set maximum price. For 1976-1989 the series distinguishes regulated ceilings from reports of free-market prices. Market Order 14/1989 does NOT lift it: it replaces the fixed ceiling with a formula tied to the cost of meat. Each year identifies its source type; a ceiling is not a market average.

Shrinkflation

Less quantity for the same price. Establishing it for a gyro wrap requires comparable weight and composition measurements over time. Price ratios alone do not establish a change in grams.

Quality adjustment

Restating the price for a common reference product. In this model it depends on assumptions about wrap weight and composition; it is not a second observed shop price.

Uncertainty range

Price bounds come from the source range or declared model assumptions and may be asymmetric. They are not a statistical confidence interval or a measure of variation across all shops.

Input categories A-D

A: Model price anchor; source verification is separate; B: Regulated, single-source or an estimate with a range; C: Interpolated between model anchors; D: Interpolated inside the price-control era, or projected outside the documented range. Categories describe how the price enters the model. They do not certify original-source verification, representative sampling or historical product composition.

Wage basis

After contributions, before income tax. Annual income divided by 12, using 14 payments throughout the series. Wage and contributions are twelve-month means. Purchasing power in classic gyros.