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that a more complete evaluation of management suc- 
cess includes changes that occur in the harvesting sec- 
tor and how the people who depend on the resource for 
their livelihood are impacted by management choices. 
An initial set of indicators developed in the U.S. north- 
east region were broken into 5 broad groupings: finan- 
cial viability, distributional outcomes (i.e. distibution 
of benefits and costs of a program among individuals, 
groups and communities), governance, stewardship, 
and well-being of fishermen and fishing communities 
(Clay et al., 2014). The choice of these categories was 
the result of a collaborative effort among economists 
and other social scientists in the northeast region. 
Among the indicators of financial improvement, a 
change in productivity, hereafter “productivity change,” 
has been the focus of a concerted effort within the U.S. 
National Marine Fisheries Service (Walden et al., 2012, 
2015; Thunberg et al., 2015). Simply put, productivity 
change describes how the landings from fishing vessels, 
and the inputs (fuel, labor, materials) used to produce 
those landings change through time. This indicator is 
important because productivity change is directly tied 
to profit change. If, for example, prices for the fish 
landed are stable, and the inputs such as fuel used on 
a fishing trip do not change, profits can increase if ves- 
sels are able to produce more landings (outputs) for a 
given level of inputs. 
Because fishing vessels typically land more than one 
species of fish and use several different inputs such as 
fuel, labor, and vessel capital to land fish, in order to 
measure productivity, both landings and inputs need to 
be aggregated into single values. Combining input and 
outputs into single values is typically done with aggre- 
gators, which are determined by either nonparametric 
or parametric programming methods, or by prices. In 
this article, we use prices to aggregate inputs and out- 
puts. Once the landings produced (noted as W’) and the 
inputs used (noted as “X’) are aggregated into a single 
value, in any time period, productivity can be viewed 
as either the ratio of the output value aggregate Q(Y) 
to the input value aggregate Q(X) (i.e., TFP-QCY) / 
Q(X)), or the difference between the 2 quantities (i.e., 
TFP=Q(Y)-Q(X)). According to Diewert (2005), if the 
ratio measure of TFP is used (i.e. Q(Y)/Q(X)), the re- 
sulting measure is called an index, whereas if the sec- 
ond additive definition is used, the measure is called 
an indicator. In order to assess how productivity has 
changed between time periods, referred to as t and 0, 
productivity change is then either TFP t /TFP 0 , or TFP t 
- tfp 0 . 
There have been a large number of studies in which 
an index number is used to measure change in produc- 
tivity in fisheries (Squires, 1992; Jin et al., 2002; Fox 
et al., 2003; Brandt, 2007; Stephen and Vieira, 2013; 
Walden and Kitts, 2014; Pan and Walden, 2015). The 
difference between these studies was usually in the 
way in which the index number was constructed, and 
in the prices used to weight the inputs and outputs. In 
recent reports by the U.S. and Australian governments, 
index numbers were used to track trends over different 
time periods for multiple fisheries (Stephen and Vieira, 
2013; Walden et al., 2015). However, there have been 
no studies that we are aware of in which an indicator 
has been used to measure changes in productivity in a 
commercial fishery. 
In this study, we introduce and measure change 
in productivity on the basis of differences with the 
Bennet-Bowley (BB) indicator. The BB indicator is 
an attractive method to measure productivity change 
because it can be easily constructed in spreadsheet 
software and it has additive properties that allow one 
to construct the indicator at the vessel level and then 
aggregate results to the overall fishery level. It does 
not require complex statistical or aggregation methods 
to measure a change in productivity. Our work contrib- 
utes to fisheries productivity studies by showing how 
the BB indicator can be constructed to examine change 
in productivity, and how it can then be aggregated to 
the fleet or fishery level. Therefore, the BB indicator 
becomes another measure of productivity that can be 
added to the growing toolbox of techniques used to 
measure a change in productivity in commercial fisher- 
ies. We also show how a simple volume indicator can 
be constructed to measure changing biomass, which 
can then be combined with the productivity measure 
to arrive at a measurement of biomass-adjusted pro- 
ductivity. As far as we know, our study is the first that 
specifically uses the BB indicator to assess change in 
productivity in a commercial fishery. 
The BB indicator is used to measure change in pro- 
ductivity in the northeast multispecies fishery (i.e., 
groundfish fishery) over a period covering the transi- 
tion to catch share management. It is used to examine 
both the contribution of vessels entering, exiting, and 
continuing within the groundfish fishery to productiv- 
ity change, and also the impact of changing species mix 
and quantities of inputs used on productivity. Results 
show a significant decline in productivity after conver- 
sion to catch shares — a decline caused by declines in 
output quantities, and an overall decline in produc- 
tivity among “continuing” vessels. Because continuing 
vesssels composed the largest vessel group, they had 
the most influence over total change in productivity. 
Breakdown of the BB indicator into groups of outputs 
and inputs showed that declines in quantities of out- 
puts overwhelmed declines quantities of inputs after 
the catch share system was incorporated. Although ves- 
sels were able to reduce their use of inputs somewhat, 
the influence of declining outputs was greater and re- 
sulted in negative productivity. Until there is further 
growth in outputs resulting from improved biomass, or 
consolidation of the fleet, increases in productivity are 
unlikely to occur. 
Materials and methods 
We are interested in measuring both the overall pro- 
ductivity change at the fishery level, and the contribu- 
tion of different segments of a fishing fleet to a change 
