The CPT recommends that the Gmacs Base model be used for OFL and ABC estimation. The Gmacs Base model makes the transition from the old SMBKC model to a Gmacs model. The model improves the treatment of selectivity by constraining selectivity to be less than 1.0 for stages 1 and 2. The Gmacs Base model fits the data better than the Gmacs M model, and it does not use the Francis weights to up-weight length frequency data.
The CPT requests that the equations for the likelihoods, as well as the formula for the Francis weighting, be included in the document. For the May 2017 meeting, the CPT recommends continued exploration of data weighting (Francis and other approaches) and evaluation of models with and without the 1998 natural mortality spike. The authors are encouraged to bring other models forward for CPT and SSC consideration
CPT Recommendations 2017
The CPT recommends that the Gmacs Base model be used for OFL and ABC estimation. The Gmacs Base model makes the transition from the old SMBKC model to a Gmacs model. The model improves the treatment of selectivity by constraining selectivity to be less than 1.0 for stages 1 and 2. The Gmacs Base model fits the data better than the Gmacs M model, and it does not use the Francis weights to up-weight length frequency data.
The CPT requests that the equations for the likelihoods, as well as the formula for the Francis weighting, be included in the document. For the May 2017 meeting, the CPT recommends continued exploration of data weighting (Francis and other approaches) and evaluation of models with and without the 1998 natural mortality spike. The authors are encouraged to bring other models forward for CPT and SSC consideration