SLIDE 23 CPUE Model Structure
- Hurdle Model (two-step)
- 1. Probability of non-zero catch
- 2. Predicted CPUE given it is
greater than zero πππππ’ ππ π§ = π½π + πΈπππ π§ + π₯π§
π₯π§~π π₯π§β1, 1 π½π ~π ππ½, ππ½
2
π½ π·π π§ > 0 ~πΆππ πππ£πππ ππ π§
π·π π§ = πΏπ πβπΎππβπΎπΞ΄π§
πΏπ ~π ππΏ, ππΏ
2
ππ π§ = ππ€ Γ π·π π§ πΏπ π§ = 1 + ππ π§π·π π§
ππ π§ = π·π π§ + π·π π§ + 4ππ π§
2
2ππ π§
2
π·π π§|π·π π§ > 0 ~Ξ πΏπ π§, ππ π§ πΉ π·ππ π§ = π½ π·π π§ > 0 Γ π·π π§|π·π π§ > 0
23