Estimating economic gains for landowners due to time-dependent changes in biotechnology

This paper presents a model for examining the economic value of biotechnolo gical research given time-dependent changes in biotechnology. Previous pape rs examined this issue assuming a time-neutral change in biotechnology. How ever, when analyzing the genetic improvements of increasing a tree's resist ance to a pathogen, this assumption is untenable. We derive analytical expr essions for the optimal rotation age given nonconstant changes in biotechno logy. Our model is then implemented using (1) growth and yield simulations, (2) optimal rotation calculations, and (3) survey data on genetic resistan ce of slash pine (Pinus elliotti) to fusiform rust. Non-parametric regressi on models are used to estimate the economic gain functions which, for the c ases considered, averaged about 1% of forestland value per year.