290 likes | 419 Views
A State Space Bioeconomic Model of Pacific Halibut. Keith R Criddle, Utah State University Mark Herrmann, University Alaska Fairbanks. Halibut Landings. IPHC regulatory areas. Approximate Structural Model with Aoki State Space Time Series Error Correction. Model Solution.
E N D
A State Space Bioeconomic Model of Pacific Halibut Keith R Criddle, Utah State University Mark Herrmann, University Alaska Fairbanks
Approximate Structural Model with Aoki State Space Time Series Error Correction
Model Solution • GLS solution to equation 1 • GLS solution to equation 2 with bias correction • Aoki State Space Time Series Analysis solution to equations 3 & 4 • Iterate steps 1, 2, and 3 until parameter estimates converge
Convergence of Parameter Estimates Stock Dynamics Recruitment
Sustainable Yield and Recruitment: ± 10% Change in Productivity
Sustainable Yield and Recruitment: ± 10% Change in Recruitment
Sustainable Yield and Recruitment: ± 5% Change in Growth Rate
Market Model US Wholesale Demand R2 = 0.871 US Inventories R2 = 0.446 BC Exports R2 = 0.795 BC Export Price R2 = 0.946 AK Exvessel Demand R2 = 0.899 BC Exvessel Demand R2 = 0.882
What Next? • Age/Sex structure to stock and recruitment dynamics • Spatial structure to stock and recruitment dynamics • Use ENSO instead of PDO to gain from lag • Include model production costs • Stochastic Optimal Control of catches and inventories