8.1. The indexes currently included in Catalogue No. 6410.0 were first published in the October 1972 issue of Price Indexes of Metallic Materials (6410.0) as the Price Indexes of Copper Materials Used in the Manufacture of Electrical Equipment. In January 1986, the title of that publication was changed and the series for the other metallic materials (iron and steel, aluminium, copper and brass, and zinc) were transferred to Price Indexes of Materials Used in Manufacturing Industries, Australia (6411.0).
8.2. The first series was published on a reference base of 1968-69 = 100.0 and provided monthly index numbers from July 1968 to August 1983. A description of the first series, including its composition and weighting pattern, is given in the October 1972 issue of Price Indexes of Metallic Materials (6410.0) and in Labour Report No. 57 1972.
8.3. From September 1983 to May 1984 the publication of the series was discontinued because serious deficiencies had been detected in the samples of prices used.
8.4. Revised series, on a reference base of 1983-84 = 100.0, were introduced in June 1984 and provided revised monthly index numbers from July 1983. The appendix to the June 1984 issue of Price Indexes of Metallic Materials, Australia (6410.0) provides a detailed description of the revised indexes, including their composition and weighting.
8.5. The change to the publication in January 1986 did not include any changes of substance for these series. They are still published on a reference base of 1983-84 = 100.0 and use the composition and weighting pattern that was introduced in June 1984. From September quarter 1997 the indexes have been compiled and released quarterly.
Nature and purpose
8.6. The publication contains index numbers for copper materials used in the manufacture of three types of electrical equipment, namely:
- industrial electric motors;
8.7. The index for industrial electric motors is intended to measure price movements of copper materials used in manufacturing electric motors intended for industrial applications only. As a result, this index does not necessarily reflect the price movements of copper materials used in the manufacture of other smaller types of electric motors, such as those used as components in white goods or other domestic appliances.
8.8. The indexes are used primarily for adjusting business contracts.
Composition and weighting
- distribution transformers; and
8.9. The items included in each index, and their percentage contributions, are shown in Table 8.1: Price indexes of copper materials
8.10. It should be noted that some items are included in more than one index. Enamelled winding wire is an item in both the industrial electric motors index and the distribution transformers index; strip is included in all indexes; and busbar is included in the industrial electric motors index and power transformers index. The types of each material priced reflect those actually used in the manufacture of each type of electrical equipment. For example, the prices for strip reflect the current usage of paper covered strip, enamelled strip or bare strip in each type of equipment.
8.11. The items were selected and allocated weights in accordance with the estimated average values of copper materials used in the manufacture of each type of equipment in the year 1982-83, and revalued to the relevant prices applying in the reference base year of 1983-84.
8.12. The weights attributed to each of the items in the indexes reflect the average usage by industry in 1982-83 and, as such, do not necessarily reflect the relative values of materials used by particular manufacturers.
8.13. Price collection is spread across the three months of the quarter. Prices relate to specified standards of each material and are those charged by manufacturers or distributors of copper materials to electrical equipment manufacturers.
8.14. The point of pricing is 'delivered into store'. As far as possible, actual transactions prices are used.
8.15. There are two broad levels at which weights are used in the compilation of index numbers. At one level are the item weights, which were mentioned earlier and are provided in Table 8.1. These weights are commonly called regimen item weights and are fixed between the periodic reviews of the whole index. For these indexes, the values used were derived from data supplied by a sample of manufacturers for representative types of equipment in each category.
8.16. At the other level are the sample weights. These weights are kept under continual review in accordance with the program of sample review and maintenance discussed in Chapter 12. The main data source for determining sample weights is the suppliers of copper materials to manufacturers; weighting information is obtained by personal interview.