The New Member Problem in the Cooperative Management of the Northern Atlantic Bluefin Tuna*

In this paper the new member problem faced by the regional fisheries management organisations is discussed for a typical highly migratory species: the northern Atlantic bluefin tuna. The analysis is based on simulation and optimisation results from a bio-economic model. The results, for both the East and the West Atlantic stocks, show that presently the threat of the new members is not relevant for the breakdown of the cooperative management. This is due to the very low level of the stock, which makes non-cooperation a low payoff strategy. As the optimal cooperative strategy calls for an initial harvest moratorium the threat becomes progressively more relevant, showing that this is a dynamic problem which is aggravated in the long run. Two possible solutions for this problem are simulated: “transferable membership ” and “waiting period”. The simulation results show that a “transferable membership ” scheme, if properly implemented, is fully efficient in protecting the cooperative agreements of the regional fisheries organisations from the free rider actions of the prospective new members. The “waiting period”, although protecting the member countries generally does not preclude such behaviours