A State Space Bioeconomic Model of Pacific Halibut

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A State Space Bioeconomic Model of Pacific Halibut

• Keith R Criddle, Utah State University
• Mark Herrmann, University Alaska Fairbanks

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Halibut Landings
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IPHC regulatory areas
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Approximate Structural Model with Aoki State
Space Time Series Error Correction
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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

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Convergence of Parameter Estimates
Stock Dynamics
Recruitment
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Stock Dynamics
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Recruitment Dynamics
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State and Observation Equations
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Decay Path of Latent Variables
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Gain from State Space Error Correction Procedure
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Expected Sustainable Yields
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Expected Recruitment
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Sustainable Yield and Recruitment 10 Change
in Productivity
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Sustainable Yield and Recruitment 10 Change
in Recruitment
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Sustainable Yield and Recruitment 5 Change
in Growth Rate
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Product and Financial Flows in the Halibut Market
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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

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Economic Effects of IFQs
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Expected Effects of Season Elongation
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Expected Effects of Increased Aquaculture
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Sustainable Exvessel Revenues 10 Change in
Productivity
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Sustainable Exvessel Revenues 10 Change in
Productivity
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Sustainable Exvessel Revenues 10 Change in
Recruitment
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Sustainable Exvessel Revenues 10 Change in
Recruitment
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Sustainable Exvessel Revenues 5 Change in
Growth Rate
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Sustainable Exvessel Revenues 5 Change in
Growth Rate
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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

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The End