UW Aquatic & Fishery Sciences Quantitative Seminar

Andrew Scheld

UW SAFS

Weak Stock Avoidance: New Theory & Empirical Analyses

Abstract

Choke species – stocks with low allocations which limit total fishery production due to imperfect selectivity – present a major challenge to management of multispecies fisheries using output controls. In this talk, a simple theoretical model of individual decision making in a regulated multispecies fishery provides insight into exogenous conditions which may result in choked joint production. This model motivates two empirical analyses which explore avoidance behavior in New England Multispecies groundfish following their transition to catch share management. First, non-parametric data envelope analysis is used to construct joint production frontiers and estimate the cost, in terms of foregone landing revenues, of weak stock avoidance. Then, a Bayesian hierarchical model of Multispecies groundfish production yields marginal rates of product transformation between a weak stock and the aggregate species complex which suggest costly avoidance. Empirical results in general provide support for the presented theoretical model and indicate a need for advancement of production theory and empirical methods which can accommodate technology exhibiting costly disposal properties.