Continuous vs discrete-time bioeconomic models: Seasonal fisheries

Abstract

We develop a discretization method of continuous-time bioeconomic models which consists of two steps: first we estimate a proper growth function for the continuous-time model through the ensemble Kalman Filter. Then we use the Runge-Kutta method to analyze the optimal management of seasonal fisheries in a discrete-time setting. We analyze both the case of quarterly harvest and the case of monthly harvest, and we compare these to the case of annually harvest. We find that seasonal harvesting is a win-win optimal solution with higher harvest, higher optimal steady state equilibrium, and higher economic value. We also demonstrate that the discretization method overcomes the economic and biological weakness and preserves the strengths of both continuous and discrete-time bioeconomic models