has already led to a conceptual difficulty." 

 There is some evidence that in certain of the 

 populations which historically were overfished 

 the costs to society of rehabilitation of the 

 populations exceeded the benefits from the 

 subsequent higher yields which resulted from 

 the imposition of the biological control pro- 

 gram required to obtain the maximum sus- 

 tainable yield. 



The debate between economists and biolo- 

 gists over the "success" or "failure" of the 

 International North Pacific Halibut Commis- 

 sion as an instrument in fisheries manage- 

 ment is an illustration of this type of difficulty.'* 



Aggregate Yield and Biological 

 Models of Particular Species 



A more subtle set of difficulties is involved 

 in the interrelationships between an aggregate 

 yield function and the partial yield functions 

 derived by the biologists for particular popu- 

 lations. In the recent development of the eco- 

 nomic literature on fisheries the economists 



^ More precisely, if biological overfishing has occurred, 

 and if a population is pushed well beyond the second 

 equilibrium point, does it enhance the material well- 

 being of the society to spend time and money (labor 

 and capital) to restore it to the second equilibrium? 



^ It is also appropriate to point out that the Halibut 

 Commission has been an important training ground 

 for biologists interested in population dynamics and 

 fisheries management problems, a benefit not included 

 in the economic calculus. And also it is important 

 to note that there should be a clear distinction between 

 population dynamics as part of an academic discipline 

 and the administrative process of a social institution 

 such as a commission. The two activities have differ- 

 ent goals, but in the field the practitioners interact so 

 closely it is difficult for outsiders to observe the dis- 

 tinction. For a biologist's view of the Halibut Com- 

 mission's work, see Schaefer (1970a, p. 14). Another 

 illustration may be in the sea lamprey control pro- 

 gram. 



Since the economist, like St. George, traditionally 

 defends the general welfare — the maximization of 

 Gross National Product — of the society against the 

 onslaught of particular interests it seems appropriate 

 to me to make this argument an economic one. What 

 is omitted, however, from the economic analysis is 

 adequate consideration of the place (role) of any par- 

 ticular species in the ecological stioicture. This omis- 

 sion, together with the usual inadequacy of the defini- 

 tion of the appropriate rate of social discount, is 

 probably sufficiently important to make one want to 

 proceed with care with a decision to fish out a resource. 

 It does not follow, however, that such a resource 

 should be "saved" by a costly biological rehabilitation 

 program. 



have looked to the biologists' yield function 

 for a particular species as the source of the 

 production function upon which subsequent 

 economic analysis of the fishery can rest. 

 This development is logical in that the most 

 money for biological research has been spent 

 (for the most part) on those populations that 

 are economically interesting. More directly 

 put, the market demand for fish has been an 

 important determinant of the direction of 

 application of biological work. 



In the historical development of ocean fish- 

 eries the interaction between market forces 

 and biological limits on the supply represented 

 by specific fish populations has been a typical 

 case of exploitation at an extensive margin. In 

 the long run, for certain fisheries (given a posi- 

 tive income elasticity of demand) operating on a 

 particular stock of fish, there has been a ten- 

 dency for the fishery to extend itself both geo- 

 graphically and temporally. If, after this ex- 

 tension has taken place, we assume that through 

 the imposition of biological regulation the 

 supply function for the stock in question be- 

 comes infinitely inelastic, economic adjustments 

 will take place and the fleet will tend to move 

 on to another similar stock or perhaps to a com- 

 pletely differentiated stock. 



Thus we have the development of fisheries 

 management essentially on an ad hoc basis 

 as a response, often belated, to the expansion 

 of fi,shing effort against a finite supply of fish. 

 The continuous expansion of fisheries at the 

 margin (taken collectively) has resulted in an 

 aggregate supply curve which has been elastic. 

 World production of protein from the oceans 

 has risen and is expected to continue to rise. 

 The ultimate limit will be determined by a 

 trade off between the capacity of the basic 

 chemical biological processes of the oceans 

 to produce protein and the cost of collecting 

 it.** At the same time the expansion in world 

 fisheries has tended to conceal the condition 

 of the specific stocks already exploited and 



^ The inputs, the labor and capital utilized to bring 

 about the increase in aggi'egate output of fish are 

 not on the average highly specialized. Both are able 

 to shift from one -fishery to another. Vessel construc- 

 tion and reconditioning is a relatively easy process. 

 Labor immobility is a larger problem but it is less 

 acute in high seas than in inshore fisheries. 



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