The auction centres for wool in Australia are located in three regions, Northern (Sydney, Newcastle, Goulburn), Southern (Melbourne, Geelong, Adelaide, Launceston) and Western Australia (Fremantle). In an auction, raw wool is sold using the greasy price, expressed in cents per kilogram. This can be converted to a clean price estimate by multiplying greasy price by 100 and dividing by the yield. Here yield is the estimate of the clean fibre either after washing/scouring or processing of greasy wool. The response variable is the clean price in c/kg, which is the base price less the total discount. The base price for wool for a given style and fibre diameter (micron), assuming there are no faults for strength, length, vegetable matter or colour is expressed in c/kg clean.