§ Mr. Summersasked the Minister of Labour if he will provide a table showing the approximate value of Customs or Excise duties and Purchase Tax on the assumed quantities of items so taxed used in the calculation of the Interim Index of Retail Prices under the following heads: food, clothing, household durable 159W goods, miscellaneous goods, drink and tobacco.
§ Mr. IsaacsThe Interim Index of Retail Prices is not calculated by aggregating the costs of particular quantities of the various items included in the index. It measures the average percentage change, from month to month, in the general level of retail prices of goods entering into working class expenditure, and the final index is a weighted average of the percentage changes for each of the seperate items. A full description of the method of calculation of the index is given in "Interim Index of Retail Prices: Methods of Construction and Calculation" published by H.M. Stationery Office.