infinity, the derived equilibrium yield function

 7402 7132 .3406 (
 Ce = exp (3.155e)V7402 X X (79)
 e t it 2t


is obtained.5 An identical derivation can be used for any other state

in the GMRFF. The derived equilibrium catch functions for each state in

the GMRFF with fishing power fixed at 1975 levels in each state are

shown in Figure 13. The catch equations in Figure 13 must be interpreted

with some caution. Mississippi vessels can be seen to have a much

greater average productivity per vessel than any other reef fishery

state. A major factor that must be considered, however, is that

Mississippi vessels exhibit a much greater average fishing power per

vessel that other states' vessels. Thus, the figure does not accommodate

a direct comparison of the relative productivities of vessels in dif-

ferent states. The reason is that each catch equation is expressed in

terms of vessels where the average fishing power per vessel varies

across states. Nonetheless, the functions correspond to the class of

derived equilibrium yield functions discussed in Chapter III.


Productive Interdependence and Average Productivity

 The notion of average productivity of vessels fishing different

grounds was a key element in some of the incipient work done on the

common property nature of fisheries production (Gordon, 1954). More

specifically, it was argued that productive interdependence and the

absence of property rights would lead to a situation where fishing


 5Equation (79) illustrates the fact that any level of effort can be
chosen as long as it remains fixed for a sufficient amount of time to
enable the autoregressive process to converge to zero.