Airfare Price Index (APIx)

Statistical release · for augmentation of the Consumer Price Index
Ministry of Statistics & Programme Implementation
Problem statement SIH26056
Airfare inflation
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Index level
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Release status

What this measures

Air fares are collected automatically from travel portals every ten minutes, across a fixed basket of the fifteen busiest domestic city pairs and five booking lead times. For each route and lead time the cheapest available fare is recorded — the price a traveller could actually have transacted at. Those prices are converted to a single index using the geometric (Jevons) method, weighted by each route’s share of scheduled seats. The resulting movement is airfare inflation, which is the input a consumer price index requires for air travel.

CPI basis and producer-price (SPPI) basis

Purchaser price CPI input
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Producer price SPPI input
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Wedge on identical cells
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purchaser price (CPI basis) producer price (SPPI basis), same cells
What each index counts
Ticket componentGoes toCPI basisSPPI basis
Base fareairline✓✓
Fuel & airline surchargesairline✓✓
GST on fare (5%)government✓cancels
Aviation Security Fee ₹236government✓✗
UDF departing + arriving (+18% GST)airport✓✗
OTA convenience feeportalnot in listingnot in listing
Used forCPI · DA · RBI targetISP & GDP deflator
Wedge by route, latest day producer − purchaser, index points, same cells
CPI basis     APIxt   = 100 × exp( Σ wi · ln( Pi,t / Pi,0 ) / Σ wi )
SPPI basis    APIx-Pt = 100 × exp( Σ wi · ln( (Pi,t − Ci,t) / (Pi,0 − Ci,0) ) / Σ wi )
where         Ci,t = ASF + 1.18 · [ UDFdep(origini, t) + UDFarr(destinationi, t) ]
GST cancels  P = 1.05 · F + C  ⇒  (P − C) / (P0 − C0) = F / F0
Pass-through charges by departure airport

Route-level heat map

Index by city pair and booking lead time, against the reference period. Lighter cells are cheaper than the reference period, darker cells dearer. T+7 means booked seven days before departure (the T−7 bucket in the problem statement). A cell at 0% means the cheapest fare bucket has not moved — hover any cell for the fares behind it. Blank cells had too few observations to price reliably and are excluded rather than estimated.

    Fare spike alerts

    City pairs whose index has moved beyond ±15% from the reference period. The threshold is fixed in advance so that flagging is not a judgement made after seeing the data.

    Seasonal and temporal trends

    Index movement over the collection period, and average fare by day of week. Day-of-week effects are a known driver of airfare seasonality; the pattern firms up as more weeks are collected.

    Airline comparison

    Each carrier's cheapest fare in a cell (route × lead time × day) against the cheapest anyone offered in that cell, over every observation. Controlling for route is what makes carriers comparable — a raw mean fare mostly reflects which routes a carrier flies.

    Data access for statistical systems

    The index is machine-readable. Central statistical systems can ingest it directly rather than transcribing from this page.

    API documentation
    GET /api/v1/apix?month=YYYY-MM
    GET /api/v1/apix/latest
    GET /api/v1/sppi?month=YYYY-MM
    Authenticated with an X-API-Key header. Every response carries the reference period and the method used, so an ingested figure can never be separated from how it was produced.
    Methodology, coverage and data provenance for statistical review