The Nash-Cournot approach to shared fish Stocks: An empirical investigation

The Nash-Cournot equilibrium in a competitive fisheries game leads to severe depletion of fish stocks compared with a cooperative solution. We review the Nashequilibrium solution and how it depends (i) on the number of identical players and (ii) the share of the dominant player in a two player game. We then investigate what has happened in two shared stock fisheries in the Northeast Atlantic where stock sharing agreements have broken down recently. Have these fisheries moved closer to a Nash-Cournot equilibrium as a result? Contrary to expectations, we find that the rate of exploitation in these fisheries has not increased as a result of a breakdown of sharing agreements. In conclusion, we offer some thoughts on why the Nash-Cournot approach may not be appropriate for shared fish stocks.