Operational tools and adaptive management

R
FC
2
1
pqx
*
Whereas the equilibrium incentive parameter for the cod fisheries is given in (33), the
corresponding variable for the authorities is found by inserting (33) into (32). This yields;
2
MS
2
2
MS
2
F
2
2
F
2
2
FC
2
MS
2
MS
2
F
2 2
F
MS
( ) ( ) pqx
w *
(48)
The sign of (48) can not be determined unambiguously. If the cod fisheries are strongly
negatively affected by the nephrops fisheries, i.e.
FC
*
2 is high, w 2 will be low. The reason is
that a high
FC
2 contribute to a high tax set by the cod fisheries, then in order to limit the
deterring effect on effort in the nephrops fisheries the authorities set a low tax, or even a
subsidy, that is w 0
*
2 . High economic interests on behalf of the authorities,
MS
2 has
(partly) the same effect, as this means that the authorities are interested in promoting effort.
The net incentive parameter, i.e. the aggregate of the two incentive parameters, is given by
w 2 * *
MS
2 (
F
)
MS
F
2 (
MS
)
F
FC
2 pqx
MS
2 ( 2
MS
1)
F
2
F
2
(49)
2 2 2 2
2 2 2 2
The reaction functions show that whereas the authorities take the incentive scheme (parameter
v) of the cod fisheries into consideration when fixing its incentive parameter, the same is not
true for the cod fisheries. When the cod fisheries get a say in the management of the nephrops
fisheries they set the incentive parameter independently of the authorities‟ regulations, and
from (33) it is easy to see that they set a tax on effort (v*>0). The authorities, on the other
hand, in formulating their incentive scheme they first outdo some of what the cod fisheries
have put into the scheme. This means that compared to a situation where the cod fisheries had
no say in the management of the nephrops the authorities now reduce the incentive parameter.
The reason is that the authorities in addition to having interests that imply to deter (tax) effort,
they also have interests that imply to promote effort (economic and social interests). In order
to moderate the effect of the cod fisheries‟ tax on effort they reduce their incentive parameter,
which means either a lower tax or a higher subsidy, or a higher likelihood for subsidising the
nephrops fisheries. They do this motivated of their economic and social interests.
A4.3 The sardine purse seine fishery
The objective functions of the authorities, fishers and MSC are now given by (7), where w is
now substituted by w3 and μ by μ3, (2) has got an extra term given by
substituted by ψ3. The objective function of the MSC is given by
2 ( z zE)
and ψ is
MSC
MSC
MSC
2
M
U 1 F(
x)
qxE 2 ( pqxE aE ) 3 ( E E ) ( z0
Solving the model given by (1), (2) and (16), with the corrections above, as a common agency
gives the following reaction functions for the incentive parameters:
MSC
zE)
(47)
(51)
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