The use of registers in sampling of outlets and routines for drawing and inclusion of new outlets CPI workshop Istanbul, 10 – 13 October 2011

Data sources in CPI Around 2200 outlets –Questionnaire – around price obs. –Price collector for introduction Scanner barcode data –Around obs. monthly Rents –2500 households, monthly by telephone interview Central collection –Websites - monthly Municipal-State-Reporting –431 Municipalities, twice a year

The use of register Business- and enterprise register –Sample of outlets –Sample of supermarkets (food and everyday commodities) ”Central Population Register” and ”Ground Property, Address and Building Register” –Sample of tenants

Business register Population: –all industries according to NACE standards (SIC2007) –all establishments with active operations in Norway the previous year Updated first of January in the statistical year

Business register, cont. Out of date information caused by lags in the registration Drop outs registered some time after they occur –Final figures for drop-outs in year t is first available when publishing the figures for year t+2 Some outlets are not correct registered regarding to industrial codes/economic sectors

Sampling of outlets Business register is reduced to specific industrial codes (nace) Norway divided into 8 geographical regions Sampling frame: –all establishments defined as the industries 45, 47, 55, 56, 77, 95 and 96 within each geographical regions Probability sampling – turnover figures –The probability increase with increasing turnover –Turnover is defined as the sum of remuneration of sale to customers Rotation of outlets –1/6 of the sample is rotated each year

Sampling of outlets, cont. All new outlets receive a letter with information about the CPI and the requirement –The possibility to file a complaint All new outlets get a visit by a price collector The gross sample is reduced to a net sample by: –Removing outlets that are closed down –Removing outlets that are registered in wrong industrial code –Removing outlets that do not have the relevant range of goods

Sample of supermarkets Purpose: sample of supermarkets – food index Sampling frame: –All establishments defined by industries in and (nace) –companies belonging to the major supermarket chains provided that they can deliver scanner bear data The sample is drawn after proportional allocation by turnover stratified by chain profile –A chain profile with high turnover will have more supermarkets in the sample –Around 180 supermarkets makes the sample

”Central Population Register” and ”Ground Property, Address and Building Register” Purpose: Sample of tenants Registers of rental units and of tenants are incomplete Potential population of rental units/tenants is established through connecting different registers Remove owner-occupiers/addresses –If owner of the house is not living at the address – a potential rental unit

Sample of tenants Random selection of persons/addresses from the population of potential rental units. Gross sample in is almost persons/addresses –Overrepresentation of Oslo residents The size of the net sample around 7000 tenants