Journal of Forest Economics 11 (2006) 245–260 Effects of resin tapping on optimal rotation age of pine plantation Zanxin Wang a,Ã , Margaret M. Calderon b , Myrna G. Carandang b a Jiangsu Polytechnic University, Changzhou City, Jiangsu Province, PR China b Institute of Renewable Natural Resources, University of the Philippines at Los Ban˜ os, Laguna, The Philippines Received 23 February 2005; accepted 14 October 2005 Abstract This paper analyses the effects of resin benefit on the optimal rotation age of Simao pine plantation. Timber growth and resin yield functions were first derived, and then an integrated formulation for Hartman rotation was solved by taking both timber and resin benefits into consideration through numerical optimization. Empirical results indicate that: (1) the inclusion of resin benefit results in lengthening optimal rotation age; (2) resin benefit has a greater effect on rotation age when discount rate is low than when it is high, ceteris paribus; (3) with an improvement of site productivity, resin benefit has a decreasing effect on rotation age, other factors being constant. These effects are also true with respect to benefit gains in present value. r 2005 Elsevier GmbH. All rights reserved. Jel Classification: Q230 Keywords: Pine plantation; Resin benefit; Rotation age ARTICLE IN PRESS www.elsevier.de/jfe 1104-6899/$ - see front matter r 2005 Elsevier GmbH. All rights reserved. doi:10.1016/j.jfe.2005.10.001 Ã Corresponding author. E-mail address: wzxkm@hotmail.com (Z. Wang).