§ Dame Peggy FennerTo ask the Chancellor of the Exchequer what is the basis upon which the Central Statistical Office calculates the monthly retail sales figures; upon how many returns from retailers these statistics are700W based; and what types and sizes of retailers are represented in the sample to ensure that the sample is a true reflection of the overall structure of the retailing industry.
§ Mr. LilleyThe monthly retail sales figures are based on a voluntary inquiry which collects figures of turnover from a sample of 3,500 retailers covering about 60 per cent. of total retail sales. Provisional estimates of the monthly index are based on nearly 2,000 returns; the final index incorporates about 2,800 replies. All types and sizes of retailers are included in the sample. The method of calculation of the index uses information on the overall structure of retailing and is designed to ensure that the index is a good measure of changes in total retail sales.
Further details of the survey are given in "Monthly Retail Sales Inquiry: Summary of Principles and Procedures", a copy of which has been placed in the House of Commons Library.