Analysis of the price and availability of New Zealand wools according to their textile properties

Abstract

Models have been developed and tested to analyse the variation in wool prices and to show availability patterns for New Zealand wools in terms of the textile properties of the wools.

New Zealand Wool Board (NZWB) auction data for eight seasons were analysed using regression techniques on the textile properties of mean fibre diameter, length after processing, colour, medullation, bulk, and vegetable matter content with price.

The Wool Research Organisation of New Zealand/NZWB's CONVERT software was used to predict textile properties from the NZWB's type structure.

The price data were adjusted to remove the influences of lot sizes and market fluctuations.

By subdividing the data available into sets representing product and process suitability and demand for wools, it was found that:

1. The order of importance for textile properties varied according to product and process suitability and demand; 2. In some cases the location of the sale was a significant factor; 3. The amount of price variation that could be explained was up to 84 per cent for anyone set; and 4. The combined effect of all sets was to account for 74 per cent of the variation in price over the eight seasons.

The analysis of availability involved the use of Fourier transformations and regression techniques to determine predictions of supply. It was found that the supply patterns of New Zealand wools show:

1. Different peak supply periods for different values of any particular textile property; 2. Different peak supply periods for different textile properties; and 3. Seasonal periodicity which was generally well-defined and regular.