An aggregate sales model for consumer durables incorporating a time-varying mean replacement age

Steffens, Paul R. (2001) An aggregate sales model for consumer durables incorporating a time-varying mean replacement age. Journal of Forcasting, 20(1), pp. 63-77.

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Forecasting category or industry sales is a vital component of a company's planning and control activities. Sales for most mature durable product categories are dominated by replacement purchases. Previous sales models which explicitly incorporate a component of sales due to replacement assume there is an age distribution for replacements of existing units which remains constant over time. However, there is evidence that changes in factors such as product reliability/durability, price, repair costs, scrapping values, styling and economic conditions will result in changes in the mean replacement age of units. This paper develops a model for such time- varying replacement behaviour and empirically tests it in the Australian automotive industry. Both longitudinal census data and the empirical analysis of the replacement sales model con®rm that there has been a substantial increase in the average aggregate replacement age for motor vehicles over the past 20 years. Further, much of this variation could be explained by real price increases and a linear temporal trend. Consequently, the time-varying model signi®cantly outperformed previous models both in terms of ®tting and forecasting the sales data. Copyright # 2001 John Wiley & Sons, Ltd.

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18 citations in Scopus
15 citations in Web of Science®
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ID Code: 10660
Item Type: Journal Article
Refereed: Yes
Additional Information: For more information, please refer to the journal's website (see hypertext link) or contact the author.
Keywords: diffusion, forecasting, sales models
DOI: 10.1002/1099-131X(200101)20:1<63::AID-FOR758>3.0.CO;2-D
ISSN: 1277-6693
Divisions: Current > QUT Faculties and Divisions > QUT Business School
Copyright Owner: Copyright 2001 John Wiley & Sons
Deposited On: 12 Nov 2007 00:00
Last Modified: 05 Jan 2011 13:34

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