Scanner Data
– Discussion on the Treatment of
Discounts in the CPI
Muhanad Sammar, Anders Norberg & Can Tongur
Statistics Sweden
Disposition
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Scanner Data in the Swedish CPI
The Swedish Practice
A New System
Data file
Different Rebates and Discounts
Regulations & Guidelines
Future plans
The Price Unit’s Current Position
• Scanner data in the CPI
• One major retail chain (Approx 50%) - Daily necessities
• Pharmacies (Total data)
• The government owned chain of alcohol stores
(Total data)
• Studying scanner data from
• Two more retail chains (Approx 35%)
• A major railway operator
• Secure scanner data from
• Petrol stations
• Hardware stores
• Electrical retailers
The Swedish Practice 1
- Manual price collection (observed prices)
Store A1
Store A2
Item 1
Store An
Item 2
Item 3
Item 4
Item i
Price collector B2
Price collector B1
Price collector Bm
The Swedish Practice 2
- Transaction prices (weekly deliveries)
Store A1
Store A2
Item 1
Store An
Item 2
Item 3
Item 4
Item i
Population C2
Population C1
Population Cn
A complete system has been built
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File validation
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Selecting – fixed basket
Price validation
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File structure
Translate variables' name
Ensure the quality
Limits
Market analysis
Aggregation
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Unweighted geometric mean
Weighted arithmetic mean
Why the Price Unit went to Use
Scanner Data in the CPI?
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Better quality
Less volatile data (three weeks)
“A study on Scanner Data in the Swedish CPI”
A report by Swedish Consumer Agency
• For 9% of the items in the survey, the prices were
hard to find or could not be found at all.
• For 6% of the examined products, the prices on the
shelves and packages were different from the
purchased prices.
• Human errors
Scanner Data
- Variables
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Excel sheet
Transaction prices (=Turnover/Units Sold)
EAN codes (bar codes)
Detailed information
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Product description
Week/Year
Store
Quantity
Brand
Different Rebates and Discounts
• Member card discounts
• Bonus offers (extras) like “3 for 2”
• Sale
• Coupon discounts
Member Card Discounts
• “Membership” offers are for the moment a steadily
growing marketing strategy
• premium checks
• membership discounts
• offers on travel, hotels and various entertainments.
• For one of the retail chains, 80% of all their sales,
registered in 2011, were made by members.
• The two major chains have millions of households
tied to them through membership cards which are
used actively
Bonus Offers (extras)
- like “3 for 2”
• Example 1: Same product - $30 off
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• Example 2: Different products - $30 off
(split proportionally)
Coupon discounts
• Issued by the seller or the supplier (in paper)
• Accepted as any payment
• Issued by the seller or the supplier (Membership
card)
Regulations & Guidelines
• The review of the Swedish Consumer Price Index
(SOU 1999:124)
• HICP regulations
• Consumer price index manual: Theory and
practice (The International CPI Manual)
• National Accounts manual
Price Unit's aspiration
• Secure more scanner data
• Introduce more scanner data into the CPI
• Introduce 5 digit level COICOP (year 2014)
• Enhance international cooperation
• Exchange knowledge and expertise on scanner
data and on quality management
Summing-up
• New method of collecting prices
• Update guidelines
• Update regulations
• A promising source of data
• High quality of actual transactions
An issue of principle:
Should rebates and discounts in the Scanner
Data be included or excluded in the target price
for the CPI?