FISHERY BULLETIN: VOL. 71, NO. 4 



which have subsequently proved to be more effi- 

 cient fishing vessels. Over the 1935-69 period, 

 annual landings per tuna fisherman showed an 

 upward time trend, growing at a rate of 2.1% per 

 year. '3 



To analyze the growth in labor productivity 

 in the eastern tropical Pacific tuna fishery, we 

 specified the following explanatory variables: 

 fishing effort, or the aggregate number of stan- 

 dard fishing days; fishing effort per worker (i.e., 

 standard units of fishing effort expended per 

 worker); secular trend variable; crew size; and 

 a variable to reflect any residual increase in 

 labor productivity because of the switch from 

 bait fishing to purse seining.'* As expected, the 

 statistical analysis revealed that the buildup in 

 fishing effort displayed a negative impact on 

 labor productivity; fishing effort per worker 

 exhibited a positive influence on labor produc- 

 tivity; and the other factors were not statis- 

 tically important. The Inter-American Tropical 

 Tuna Commission apparently did a good job in 

 adjusting its effort series for the switch in tech- 

 nology over the 1960-67 period. Therefore, it 

 must be concluded that the switch in technology 

 is primarily reflected in the effort-per-worker 

 variable. A look at the effort-per-worker series 

 reveals that it increased from approximately 13 

 to 20 standard units of effort per worker from 

 1959 to 1960. Prior to 1959, the standard unit of 

 fishing effort per worker increased gradually, 

 owing presumably to more efficient use of labor 

 in searching and catching tuna. Although fish- 

 ing effort increased appreciably over the period, 

 its negative effect was greatly offset by 

 increases in effort per fisherman, resulting in an 

 annual growth rate of 2.1% over 1935-69. The 

 actual and computed (using a statistical equa- 

 tion) yellowfin landings per fisherman are 

 shown in Figure 3. 



Pacific Halibut 



Early commercial fishing for Pacific halibut 

 is considered to have commenced in 1888 when 



'3 Catch quotas of yellowtin tuna were not a tactor in 

 productivity until 1969. 



'■» The number of" fishermen employed is a series which 

 was estimated by Bruno G. Noetzel of the Economic Re- 

 search Division with the help of material published in 

 various years of the Annual Report of the Inter-American 

 Tropical Tuna Commission. 



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Figure 3. — Observed and predicted labor productivity 

 (annual landings per fisherman) for the eastern tropical 

 Pacific tuna fishery, 1935-54 and 1956-69. Estimating 

 equation: QIL = -50615 - 2.524£: + 7406£/L + 

 13501L/A:. Variables: E = effort in fishing days; £/L = 

 effort per fisherman in days; LIK = crew size. R^ = 

 0.82; D-W = 1.22; / values — E = 2.81; £/L = 8.04; 

 LIK = 1.76. Annual compound rate of growth = 2.1%. 

 Data source: Inter-American Tropical Tuna Commission. 



three sailing vessels from the New England 

 States started to fish Cape Flattery on the north- 

 west coast of Washington Territory. The rapid 

 development of the Pacific halibut fishery did 

 not occur until the 1920's. Initially, the fishery 

 for the larger vessels was conducted over 12 mo 

 of the year. Because of the possibility of over- 

 fishing, the season was legally restricted by a 

 3-mo winter closure in 1924. Since then the 

 season has been regulated by the International 

 Pacific Halibut Commission (IPHC). The fish- 

 ery is presently carried on by a mixture of 

 Canadian and U.S. longline vessels. 



Unlike other fisheries, an analysis of changes 

 in labor productivity is complicated by institu- 

 tional factors (i.e., control by IPHC of gear and 

 length of season) as well as economic and bio- 

 logical forces. Considering the entire fishery, it 

 is hypothesized that annual labor productivity 

 is heavily influenced by the following factors: 



1. Length of fishing season 



2. Aggregate fishing effort 



3. Fishing effort per worker 



4. Crew size on halibut vessels 



5. Secular time trend. 



In the Pacific halibut fishery, we used average 

 landings per man-day at sea as a measure of 



916 



