GIPIG — Geographical Indications Price Index

Scope

GIPIG covers Italian GI products that hold at least one of the following EU certification statuses: PDO (Protected Designation of Origin / Denominazione di Origine Protetta, DOP), PGI (Protected Geographical Indication / Indicazione Geografica Protetta, IGP), DOC (Denominazione di Origine Controllata) or DOCG (Denominazione di Origine Controllata e Garantita).

Version 1 covers the Italian retail channel only. Wholesale, farm-gate and export prices are not included in this version. Geographic coverage is Italy. Products are priced in EUR.

Data Sources

Retail prices are collected from seven major Italian supermarket chains with national distribution coverage:

Prices represent the actual final consumer price at time of collection, inclusive of any active promotional discount. Shelf prices before promotion are also recorded to allow discount identification. All prices are collected simultaneously for each GI product across all seven chains in a single weekly session.

Product Selection

Products are included in the index if they meet all of the following criteria:

1. GI status: The product must carry an EU-registered PDO, PGI, DOC or DOCG designation as a primary product attribute, not merely as an ingredient in a processed food.

2. Retail coverage threshold: The product must return a minimum of 5 clean observations across a minimum of 3 distinct chains in a standard weekly collection. Products below this threshold are monitored but excluded from the published index until coverage improves.

3. Identifiability: The GI appellation must be clearly identifiable from the product name as listed by the retailer. Products where the GI designation is ambiguous or where multiple competing designations could apply are excluded.

Products are classified into tiers based on their commercial profile: Tier 1 (internationally recognised, export value above €300M), Tier 2 (established within food-literate international audiences), and Tier 3 (Italian specialists and regional audiences). Tier 4 products (authentic but commercially obscure) are excluded from v1 due to insufficient retail coverage.

Form Classification

For products sold in multiple commercial formats (notably cheese), each format is classified independently and tracked as a separate price series. This prevents mixing of structurally different price signals in a single median.

Processed derivatives are excluded because they are manufactured goods that contain a GI ingredient rather than being a GI product in their own right. A formaggino al Parmigiano Reggiano is not a price signal for Parmigiano Reggiano DOP.

Unit Standardisation

All prices are converted to a standard unit prior to aggregation. This conversion is applied using the weight or volume declared on the product packaging as reported by the retailer.

Quality Filtering

Each collected price observation passes through three sequential filters before entering the aggregation stage. Observations failing any filter are excluded and logged.

Filter 1 — Form classification: Processed derivatives are dropped. All remaining observations are classified by form (whole piece, grated, shaved, snack/stick).

Filter 2 — Weight band: Observations from packs below 60g or above 2kg are excluded. Very small packs (single-serve, catering sachets) and very large packs (wholesale quantities) produce per-kg prices that are not representative of normal consumer retail pricing.

Filter 3 — Price bounds: Each category has an established floor and ceiling price. Observations outside these bounds are excluded as likely data errors or extreme outliers.

Index Construction

Outlier removal: Following quality filtering, statistical outliers are identified and removed using Tukey fences with a factor of k = 1.5 × IQR (interquartile range). For a distribution of prices P, observations are excluded if they fall below Q1 − 1.5 × IQR or above Q3 + 1.5 × IQR. This step requires a minimum of 4 observations per GI × form group to compute meaningful quartile values.

Published statistic — median: GIPIG publishes the median retail price per GI × form combination, not the arithmetic mean. The median is used because retail prices are affected by temporary promotional discounts and by premium product variants (e.g. 30-month aged Parmigiano versus 12-month), which create skewed distributions. The median is more robust to these extremes and provides a more stable reference price.

Supporting statistics published: Alongside the median, GIPIG publishes the minimum observed price, Q1, Q3, and maximum observed price for each GI × form combination. The number of clean observations and the number of distinct chains contributing to each figure are also published.

Per-store breakdown: For each GI × form combination, the median price per chain is computed separately and available in the underlying data. This allows chain-level price comparison for the same product.

Sample prices (June 2026, Italy retail):

Publication Schedule

Prices are collected every Tuesday. Data is processed, filtered and aggregated within the same session. The published index at gipig.com is updated automatically upon completion of the aggregation pipeline. The date shown on the index reflects the collection date, not the publication date.

The index has been published weekly since May 2026. Historical weekly data is archived and available for download.

Limitations

Retail channel only. GIPIG v1 covers consumer retail prices only. Wholesale prices (farm-gate, first-sale, ex-factory) are not included. Wholesale data integration is planned for v2.

Italy only. All prices are collected from Italian supermarket chains selling to Italian consumers. Export prices, import prices and prices in other markets are not covered.

Online retail prices. Prices are collected from online supermarket platforms. Online prices may differ from in-store shelf prices at the same chains, though differences are typically small for standard packaged products.

No seasonal adjustment. Prices are published as observed. No seasonal adjustment is applied. Wine and olive oil prices exhibit seasonal patterns that users should take into account when interpreting year-on-year comparisons.

Coverage threshold. Products with fewer than 5 clean observations across fewer than 3 chains are excluded from the published index in a given week. Thin coverage weeks are logged but not published.

No producer or consortium affiliation. GIPIG is independent. It is not affiliated with, endorsed by or funded by any GI consortium, certification body, retailer or government agency.

How to Cite GIPIG

When referencing GIPIG data in publications, reports or research, use the following citation formats:

For data licensing, API access or research collaboration enquiries, contact: data@gipig.com

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