Standard Industrial Classification system. These es- 

 timates are not broken down by regions of the coun- 

 try or by time other than the census year. 



Usually more than one fish product is processed in 

 or distributed through the same establishment at dif- 

 ferent seasons, with the result that costs of the total 

 operation for the year could be allocated to particu- 

 lar products on a more or less discretionary basis. 



The 4-digit census report put "canned and cured 

 seafoods"" as an industry group. Its costs and profits, 

 reduced to ratios, are applied to canned salmon and 

 canned tuna at the processor's level in this study. 

 Cost and profit ratios derived from the "fresh and 

 frozen packaged fish products'" are applied to the 

 processing of fillets and steaks ofgroundfish, salmon, 

 and halibut and the processing of shellfish products 



Table 7. — Linear trends of price changes at the ex-vessel, processing, and wholesale levels in relation to retail prices of 

 corresponding years for different finfish products during 1950-71 and shellfish products during 1959-71. 



' Relative prices are used as independent variables. Pex = ex-vessel prices adjusted to the value of a quantity equivalent to the final form 

 sold to the consumer: Pp = processor's price; Pw = wholesale price; Pr = retail price. 



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