Journal of Applied Mathematics and Decision Sciences
Volume 2006 (2006), Article ID 12619, 12 pages

A structural model with interventions for new Zealand sawn timber production

Dongwen Luo,1 Geoffrey Jones,2 and Judith Dennis3

1Fonterra Research Centre, Palmerston North 5301, New Zealand
2Institute of Information Sciences and Technology, Massey University, Palmerston North 5301, New Zealand
3Innovation and Research, Ministry of Agriculture Forestry, Wellington 4000, New Zealand

Received 16 January 2005; Revised 16 May 2005; Accepted 17 May 2005

Copyright © 2006 Dongwen Luo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Timber production in New Zealand was privatized in 1987. We examine the effects of this change on the level of New Zealand sawn timber production, and changes in the seasonal pattern, using a state-space model with intervention variables. We describe the formulation and estimation of the state-space model, and show how it can be used to examine both the structural changes around the time of privatization and the gradually evolving seasonal pattern in production. We also show how the model can be used to forecast future production.