An MP proposed by Carl Walters that modifies the TAC according to trends in
apparent surplus production that includes information from a demographically
derived prior for intrinsic rate of increase
The TAC is calculated as:
$$\textrm{TAC} = \textrm{SP} (1-gG)$$
where \(g\) is a gain parameter, \(\textrm{SP}\) is estimated surplus production,
and \(G\) is:
For Rcontrol: \(G = r (1-2D)\) where \(r\) is the estimated intrinsic rate
of increase, and \(D\) is assumed depletion.
For Rcontrol2: \(G = r - 2bB_\textrm{hist}\) where \(B_\textrm{hist}\)
is the smoothed biomass overlast yrsmth years and:
$$b = \sum{\frac{\textrm{SP}}{B_\textrm{hist}} - r} \frac{\sum{B_\textrm{hist}}}{\sum{B_\textrm{hist}^2}} $$.
The TAC is subject to conditions limit the maximum change from the smoothed catch
over the last yrsmth years by the glim argument, e.g, default values of glim = c(0.5, 2)
means that maximum decrease in TAC is 50
is 2 x average catch.