Whisky Price Index

Why there are two measures

Each market’s time index starts at 100. It measures only change within that market since the base date: Tbilisi at 105 and Whisky.de at 102 mean +5% and +2%, respectively.

Those values cannot directly tell us which place is cheaper. The separate price-level measure fixes Whisky.de at 100 and compares exact-bottle price relatives after EUR/GEL conversion. A Tbilisi value of 120 means the comparable basket is about 20% dearer.

The fixed ten-bottle basket

The basket uses recognisable representatives of different whisky categories that are tracked in Tbilisi as exact 0.7L expressions. It is not an official sales ranking: popularity is a practical selection criterion used alongside local availability and category coverage.

• 1Johnnie Walker Red Label — a recognisable mass-market blended Scotch.
• 2Chivas Regal 12 Year Old — an age-stated premium blended Scotch.
• 3Maker’s Mark Original — a widely known wheated Kentucky straight bourbon.
• 4Jack Daniel’s Old No. 7 — a defining mass-market Tennessee whiskey.
• 5Jameson Original — a widely distributed blended Irish whiskey.
• 6Bushmills 10 Year Old — an age-stated Irish single malt.
• 7Glenfiddich 12 Year Old — a recognisable Speyside single malt.
• 8The Glenlivet Founder’s Reserve — an accessible NAS Speyside single malt.
• 9The Macallan Double Cask 12 — a premium, sherry-influenced single malt.
• 10Laphroaig 10 Year Old — a recognisable peated Islay style.

Which price enters the calculation

• Only the exact 0.7L expression; another volume, age, strength, edition, or gift set is not a substitute.
• Only a publicly displayed current price for an available listing; delivery, service, and membership costs are excluded.
• If one retailer exposes duplicate purchasable cards, its lowest public price is used so that retailer is counted once.
• The Tbilisi representative price is the median across unique retailers, limiting the influence of one unusually high or low offer.
• Whisky.de is the primary German benchmark source. If the exact 0.7L bottle is absent there, the current Weinquelle Lühmann EUR price is used; Whisky.de automatically regains priority when the exact item returns.

Time-index formula

For each bottle, the current-to-previous price relative is calculated. Comparable retailer pairs within a bottle are combined geometrically; the equal-weight geometric mean across all ten bottles then updates the previous index. This is a Jevons-type price-relative approach.

The base date is 2026-08-24 and I₀ = 100. Each new complete weekly collection creates a snapshot; historical snapshots are not rewritten.

When a bottle is temporarily missing

Absence is neither a zero price nor a price increase. Its weight is not transferred to the remaining bottles: its price relative is temporarily held at 1.00, preserving its previous contribution. When the exact bottle returns with a reliable comparable price, observed change resumes.

• 8–10Official index: enough coverage for normal publication.
• 6–7Provisional value: published with a prominent warning.
• 0–5No index value is published.

Coverage is always shown beside the value. A prolonged disappearance triggers a documented methodology review rather than a silent substitution.

Tbilisi versus Whisky.de: the price level

For every exact bottle available in both places, the Tbilisi median is converted to EUR at the National Bank of Georgia EUR/GEL rate and divided by the German benchmark price. Whisky.de is the primary source and Weinquelle Lühmann is fallback only. The equal-weight geometric mean is multiplied by 100.

Only exact 0.7L matches observed on both sides enter this cross-section, and coverage is published separately. Shipping, possible tax refunds, wages, and purchasing power are excluded: this is a retail price comparison, not a cost-of-living index.

Updates, substitutions, and limits

• The index updates only after all 13 Tbilisi sources complete a successful full collection; a partial run does not change it.
• The scheduled index refresh starts roughly 2–3 hours after the price publication. The time-series chart appears automatically only after four comparable dates have accumulated.
• German prices are normally checked on the same date. A delayed publication may use only the next calendar day's check, disclosed separately beside the index; any longer lag is blocked.
• On every index date, fallback bottles are rechecked at both retailers: an exact 0.7L return at Whisky.de immediately replaces the Weinquelle price.
• Identity matching is conservative: ambiguous names or volumes are not merged.
• The basket is fixed for comparability. A permanently discontinued bottle is replaced only through a documented methodology change with a linking treatment for continuity.
• The index describes these ten selected whiskies, not all alcohol and not any individual household’s spending.