A second class of models which correspond to those defined by equation

(42) are non-equilibrium yield functions. In these types of models,

stock effects are incorporated through stochastic processes.


Specification of Fishing Effort

 Central to.the development of an empirical representation of the

ith state's catch function is the notion of effective fishing effort.

Recall from equation (22) that effective fishing effort is primarily

composed of a nominal component and a fishing power component. Further,

fishing power was seen to be a function of input levels.

 The aggregate nature of the data must be considered in specifying

 the fishing power equation for the ith state in the GMRFF. As such, the

 fishing power function relates to the average fishing power correspond-

 ing to vessels operating out of ports located in each state. The fish-

 ing power function for the ith state is thus given by


 Sexp(k) Xl X i = 1, ..., 5 (43)
 it lit 2it t = ..., 19


 where EP denotes fishing power, Xlit is average crew size, X2it is
 it
 average vessel size (gross registered tonnage) and k is a constant

 parameter.

 The choice of average crew size and average vessel size as the

 relevant inputs for use in specifying the fishing power function was in

 part determined by available data. The nature of the fishing activity

 for vessels in the GMRFF suggest that these variables are appropriate

 measures of labor and capital inputs which determine fishing power,

 however. The general fishing process involves operating hand or power