On the Benefits of Including Age-Structure in Harvest Control Rules

Abstract

This paper explores the benefits of including age structure in the control rule (HCR) when decision makers regard their (age-structured) models as approximations. We find that introducing age structure into the HCR reduces both the volatility of the spawning biomass and the yield. Although the benefits are lower at a fairly imprecise level, there are still major advantages for the actual precision with which the case study is assessed. Moreover, we find that when age-structure is included in the HCR the relative ranking of different policies in terms of variance in biomass and yield does not differ. These results are shown both theoretically and numerically by applying the model to the Southern Hake fishery.