47 aP MR. MC. = Ck C(38) S 1 kfi aC k f. where MCi has replaces the expression r / it can be seen that the 1 sign of the difference between MR. and MC. is given by the sign of P 9P k -C Ck. From equation (31a), < 0 for all i, k and Y is ki aCi k aC k strictly positive. Therefore, the sign of the right-hand side of equa- tion (38) must be greater than zero, implying that MRi is greater than MC.. It should be noted here that a sufficient condition for MRi = MCi aP is that 0, i k. In this case, independent maximization of aC regional profits is equivalent to maximizing profit in all regions simultaneously. .th The implications of these results on input levels for the i region can be seen by examining Figure 9. The figure illustrates that equating MR. and MC. results in an output of Cli, which is greater than that produced, C2i, under the equilibrium conditions stated in equation aP (37). The distance OA-OB is equal to kC- C Taken in conjunction k=i i 1 with the nature of the yield function (equations (23a) and (23b)), it can be concluded that inputs are at lower levels when cross-regional price effects are taken into account. As in the case of a single sector fishery, the question of produc- ing at the point where price is equated to marginal cost must be con- sidered in the multi-sector fishery. As with the single sector fishery, assume that the desired yield levels have been determined for each region. In that fixing yield levels results in fixing price, the profit maximization problem reduces to a cost minimization problem with