Dynamic Theory of Fisheries Economics — Ii; Differential Game Theoretic Approach

A two countries-single speriss dynamic optimizacion problem in fisheries is formulated in differential game theoretic framework. The Cournot-Nash solution concept is introduced and two strategies in arriving at the Cournot-Nash solutions; are discussed. These strategies are (1) closed-loop catch strategy and (2) openloop catch strategy. A quadratic benefit function is then used as the objective function of each country that is to be maximized subject to a linear population-catch dynamics. Th'^ solutions are then derived for each catch strategy and their implications are d^''cussed. The major conclusions are as follows: (i) The stable optimal catches show that each country must regulate the tonal catch of her fleet, (ii) The mash-size snould also be regulated. (XXI) The opeu-locp optimal catch strategies exist only when two countries' future discount rates are the same, (iv) The higher the future discount rates, the more fish vri.ll be caught now and in the near future, and the slower the convergence of this fish population to the desired level.