The initial equilibrium age composition is based on M+F. So if there is no initial equilibrium catch, then the initial F will normally be set to 0.0 and not estimated, and the initial equilibrium age composition will be based on M.
However, it also is possible to estimate initial F without having initial catch. To do this, set the lambda on the logL for initial_equil_catch to be 0.0. Now when you let SS estimate the initial F, it will do so without any constraint or information from the input value of initial catch. This will give SS great flexibility (perhaps too much!) to steepen the initial age composition and to reduce the initial population size. So use this option with caution.
Rick
