contain no explicit constraints with respect to equating catch with

sustainable yield. However, approximate equilibrium catch functions can

be derived from those presented in Table 2 given that the autoregressive

processes in the estimated catch equations account for a portion of the

difference between predicted catch and sustainable yield.

 The derivation of such derived equilibrium catch equations rests to

a large degree on the fact that fixing effort at a given level for a

sufficient period of time will cause the resource stock to adjust to the

point where catch, corresponding to the fixed level of effort, and

sustainable yield are equated (Appendix G). Within the context of the

estimated catch equations, this stock adjustment is captured by the

estimated residual component of the autoregressive process. To see how

this process is carried out in the context of the present model, con-

sider the estimated catch equation for Florida

 S )V7402
 C t+k = exp (3.1553 + .4408Ut_) V7402 (77)

 x.7132 .3406
 It 2t


where Ct is predicted catch in time t, Utl is the estimated residual

component, Vt is number of vessels and Xit i = 1, 2 are defined as

above. If effort is fixed at time t, the expression for catch in time

t+k can be given by


 Ct+k = exp [3.1553 + (.4408)k+l U] (78)


where E denotes the fixed level of vessels, average crew and vessel size

and U represents the estimated difference between catch and sustainable

yield at the time when effort becomes fixed. By letting k approach