Weight-at-age

[jysullivan]

• [X] Use predicted values from a weight-based von Bertalanffy model instead of mean weight-at-age (especially important for older ages which are poorly represented in the data
• [X] Use survey waa instead of fishery waa in the current management model instead of fishery waa because fishery waa is biased high especially at young ages - accepted by Ben and Andrew Feb 2019
• [X] Check with Dana about when and where he uses fishery and survey weight-at-age
• [ ] In past assessments the plus group (age 42+) weight-at-age was calculated as the empirical mean weight from all samples aged 42 and older. Because this estimate was influenced by outliers, we now use the predicted value for age-42 fish from the weight-based von Bertalanffy growth model used to estimate weight-at-age for all other ages. Ben: How does this differ from something like the geometric mean?

[GreatDana]

I use the survey weight at age only (for both fishery and survey), and its LVB by sex.

Cheers, Dana

On Thu, Mar 14, 2019 at 9:05 AM Jane Sullivan notifications@github.com wrote:

• Use predicted values from a weight-based von Bertalanffy model instead of mean weight-at-age (especially important for older ages which are poorly represented in the data
• Use survey waa instead of fishery waa in the current management model instead of fishery waa because fishery waa is biased high especially at young ages - accepted by Ben and Andrew Feb 2019
• Check with Dana about when and where he uses fishery and survey weight-at-age

[image: image] https://user-images.githubusercontent.com/7398155/54375925-cfcce200-4636-11e9-8386-8d769790edbd.png

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[jysullivan]

TMB and YPR models now use exclusively survey weight-at-age for all calculations.