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There is also a question of how the use of inputs 
changes after the transition to catch shares is imple- 
mented. Again, the additive property of the indicator 
shows how vessels altered their use of inputs after the 
transition to the new catch share plan (Table 2). With 
the exception of 2011, the total amount of inputs used 
by the fleet declined. The largest decline in the use 
of inputs occurred in 2010, the first year of the catch 
share plan. This drop in inputs was expected because 
the catch share plan gave vessels the opportunity to use 
their inputs differently as their output mix changed, or 
to exit the fishery. In an output-constrained fishery, re- 
ducing the use of inputs and the cost of fishing leads to 
increasing profitability (Squires et al., 2016). 
Discussion 
The BB indicator is a powerful tool that can be used to 
assess productivity change in commercial fisheries. The 
additive nature of the indicator allows it to be used 
for examining productivity change starting at the indi- 
vidual vessel level and then aggregating the individual 
results to the fleet or fishery level. Individual vessels 
can be grouped into different categories for comparison, 
such as entering, continuing, and exiting vessels, and it 
is possible to determine which groups are contributing 
the most to productivity change. Moreover, grouping 
vessels into different fleet segments can give managers 
additional insight into changes that have occurred in 
response to regulatory actions. 
We applied the BB indicator to measure productivity 
change in the northeast multispecies fishery and found 
that productivity declined after catch shares were im- 
plemented because outputs declined more than inputs 
declined. There are a number of plausible reasons why 
outputs declined so much, but it is likely to have oc- 
curred because of lower quotas for key stocks. Because 
catches usually include a mixture of species, lower quo- 
tas for key species would constrain the catch of other 
more abundant species. These key species are usually 
referred to as “choke” species. 
The BB indicator was used to examine the contri- 
bution of entering, continuing, and exiting vessels to 
productivity change. Results showed that continuing 
vessels contributed the most to productivity change 
each year because they were the largest fleet segment. 
This specific catch share system allows incumbent ves- 
sels some degree of protection from new entrants with 
no catch history because incumbent vessels are guar- 
anteed a portion of the overall quota for each species 
for which they have catch history. As long as they can 
fish that quota profitably, they need not exit the fishery. 
The lack of improved productivity is similar to find- 
ings from studies of 2 other fisheries after implemen- 
tation of ITQ systems in other parts of the world. In 
the first, gains in economic efficiency in a Norwegian 
purse-seine fishery did not occur after transition to an 
ITQ, and this outcome was attributed partially to the 
grandfathering of fishing rights (N0stbakken, 2012). In 
a different study, after an ITQ system was implement- 
ed for the Peruvian anchovy fishery, productivity gains 
did not occur, but price increases did occur (Natividad, 
2015). Over time, there may be productivity gains both 
in these 2 fisheries and the fishery we highlighted, 
but such gains are still uncertain. Although we expect 
less productive vessels to exit over time, externalities 
still exist that work against productivity gains. For ex- 
ample, vessels can still be displaced spatially by other 
vessels. If this displacement occurs, some crews (i.e., 
vessels) may have to use more inputs to reach new fish- 
ing areas, and overall vessel productivity may decline 
depending on how all the vessels adjust their fishing 
patterns. 
An important part of any exercise that examines 
productivity trends for fisheries is adjustment for bio- 
mass change. Managers wish to know the impact of 
their policies on productivity of the fleet separately 
from any changes caused by differences in biomass. A 
volume indicator was constructed, which is similar to 
the BB indicator, to adjust for biomass in the fishery. 
The value of the volume indicator was subtracted from 
the BB indicator to arrive at a biomass-adjusted BB 
indicator. Declining biomass leads to a negative volume 
indicator, and subtracting this value means the adjust- 
ed BB indicator will be greater than the unadjusted 
BB indicator. In other words, productivity apart from 
biomass would increase. In this study, the biomass ad- 
justment did not change the sign of the BB indicator, 
but it did change the magnitude. Negative productivity 
changes were still negative, but not as negative as the 
unadjusted productivity indicator. The issue of adjust- 
ing the productivity metric by biomass change is im- 
portant, and further research needs to be conducted on 
making adjustments at the vessel level to account for 
biomass change. Because the fleet BB indicator is an 
aggregate value, subtracting the biomass indicator is 
an acceptable approach. 
Productivity change is an important economic metric 
for managers to track when gauging economic perfor- 
mance, and the BB indicator is a very easy to construct 
and flexible measure. However, productivity change is 
just one metric and needs to be combined with other 
metrics, such as price changes, profitability, and fleet 
size to give meaningful signals to managers. The north- 
east groundfish fishery is still in a transition phase in 
terms of vessels fully adjusting to the catch share sys- 
tem, and productivity gains may not be seen for several 
years, particularly if stock conditions do not improve. 
However, productivity change in a fishery will be limit- 
ed because the vessels are harvesting a finite resource, 
and in any year total output is capped by the allowable 
harvest. Fishery regulations are designed to limit out- 
put, and productivity gains will eventually peak even 
with full transferability of quota. Ultimately, managers 
may want to move toward a measure of profitability, 
rather than productivity, if there are enough cost data 
available to gauge economic performance. Profitability 
would give a better indication of the health of the fish- 
ing fleet than productivity by itself. 
