The Stability of Fishing Agreements with Entry: The Northeast Atlantic Mackerel

This paper investigates the stability of agreements for sharing fish stocks among coastal states when migrations patterns change - a heretofore largely unexplored topic. The case investigated is the agreement on sharing the mackerel stock (Scomber scombrus) in the North-east Atlantic Ocean. Since 2000, this stock has been shared by three coastal states. However, in 2007, the fish changed its migration pattern, entering the waters of a fourth state. This led to the collapse of the previous agreement in 2010, causing severe overfishing. The game of the new entrant is modeled using the partition function approach with strictly convex cost functions. The results indicate that the stability decreases with the new entrant but increases when the prices are heterogeneous. In addition, the larger players need to pay the most relatively to get the new entrant into the game.