FULLENBAUM and BELL: AMERICAN LOBSTER FISHERY 



are available for the 1950-69 period (see Appen- 

 dix Table).-^ Output per trap was regressed 

 against the number of traps and seawater tem- 

 perature on the assumption that the number of 

 traps per boat was constant. The regression 

 estimates yielded the following results: 



X = -31.82 - 0.00002807(T) + 1.846(°F) (23) 



(6.55) 



(4.99) 



R2 = 0.962 

 D-W = 2.38 



where T = 562. 8( A'): d = 0.0156; c = - 31.82 

 + 1.846(°F). In (23). T is equal to the number 

 of traps fished per year, and f-ratios are in 

 parentheses.-^ Both T and °F are statistically 

 significant at the 5% level and exhibit the cor- 

 rect sign; the Durbin-Watson statistic indicates 

 no significant autocorrelation. 



The only step required to obtain the biotech- 

 nological parameters is an estimate of the bio- 

 mass consistent with ma.ximum sustainable 

 yield. It has been calculated that (assuming a 

 temperature of 46°F) the fishable stock of U.S. 

 inshore American lobsters consistent with 

 maximum sustainable yield is equal to 31 mil- 

 lion pounds.'--^ For the Gulf of Maine (where 

 most of the resource is located), estimates of the 

 biomass were made through sampling experi- 

 ments.'-*' 



Finally, on the basis of recent cost studies, 

 we have derived an estimate of n for 1966 equal 



23 The assumption of a constant number of traps per 

 boat is necessary in order to solve for a coefficient on 

 "K". and thereby, to obtain the biotechnological paramet- 

 ers embedded in the yield-effort relationship. The rela- 

 tionship for 1966, derived on the basis of cost data ob- 

 tained from the National Marine Fisheries Service's Divi- 

 sion of Financial Assistance was 562.8 traps per full-time 

 equivalent northern lobster boat. However, it should be 

 pointed out that when the stock is large and the catch 

 high, it may pay to increase the number of traps per 

 boat: therefore, this might bias the number of "standard- 

 ized boats", but not total amount of effort. 



-'' However, the reader should note that the empirical 

 estimates themselves (1950-69) make no assumption with 

 respect to the relation between K and T. \ was regressed 

 on T and °F. Only in the simulation was a relationship 

 assumed (T = 562.SK). 



-•^ U.S. Department of the Interior. 1970. Joint master 

 plan for the northern lobster fishery. Unpublished man- 

 uscript. 130 p. (May be obtained from the National Marine 

 Fisheries Service, Washington. D.C.) 



-6 No attempts were made to run the simulation model 

 with varying sizes of the MSY biomass as this would un- 

 necessarily complicate this paper which is intended to be 

 simplistic as possible. 



to $12,070.27,28 Therefore, on the supply side, 

 the estimated parameters for 1969 are the fol- 

 lowing: 



a 

 b 

 r 



1.85379 



2.9899 X 10-^ 



5.1562 X 10-4 



$13,191 (see footnote 27). 



The Demand Function for 

 American Lobsters 



Only knowledge of d and /j is needed in order 

 to complete the empirical component of the 

 study. The estimation procedure is rather 

 straightforward. We may specify the following 

 demand function for all lobsters: 



C 



N 



= F-m(P'/CPI) + g(y/AO 



(24) 



where C is equal to consumption of all lobsters, 

 P' is the money ex -vessel price of American lob- 

 sters, Y is aggregate U.S. personal income 

 (1967 prices), A' is U.S. population, and CPI is 

 the consumer price index. Since there are no 

 exports of lobster, the following identity holds: 



C = 1+ Q + Q. 



(25) 



where /, Q^, and Q^^ are the level of imported 

 lobsters, U.S. production of all other lobsters, 

 and U.S. production of inshore American lob- 

 sters, respectively. Given (25), equation 

 (24) may be solved in terms of P, or, 



P = 



CPI 





If Qq, /, Y, CPI. and N are held constant, equa- 

 tion (26) gives a unique relationship between 

 the ex-vessel price of American lobsters and 

 quantity landed. 



Using data over the 1950-69 period (see 

 Appendix Table), the parameters of equation 

 (24) were estimated using least squares: 



-' Cost data from the National Marine Fisheries Serv- 

 ice's Division of Financial Assistance (1966) reveal the 

 following cost breakdown for a representative lobster 

 boat: operating expenses, $4,965.16: fixed expenses, 

 $1,180.20: returns to capital and labor, $5,825.48. This 

 gives a total of $12,070.84. The latter figure was updated 

 to 1969 by income increases in Maine to obtain $13,191. 



28 We will assume that rf remains constant in real 

 terms. This is equivalent to keeping our estimate of it". Tf 

 constant, while deflating all nominal variables on the 

 demand side. 



19 



