Resource Abundance, Fisheries Management, and Fishing Ports: The U.S. Atlantic Sea Scallop Fishery

The Atlantic Sea Scallop fishery has grown tremendously over the past twenty years. The location and magnitude of harvestable biomass fluctuates dramatically due to both natural variation and the explicitly spatial management system designed to allow small individuals to grow larger and more valuable. These fluctuations in natural advantages can have profound effects on fishing ports. We use methods from economic growth literature to show that ports with lower initial scallop landings have grown the fastest. Furthermore, good access to biomass influences long-run changes in landings, although this effect exhibits considerable variability across ports. We also find evidence of returns to scope, suggesting that ports with other fishing activities could be well positioned to attract new scalloping activity when stock conditions are favorable. Further investigation of the largest ports using time-series methods also shows a high degree of variability; there are long-run relationships between scallop fishing and harvestable scallop stock in some ports, short-run relationships in some ports, and no relationship between the two in others. We interpret this as evidence that heterogeneity in the natural productivity of the ocean combined with explicitly spatial fisheries management has induced a spatial component to the port-level response to changes in biomass availability.

Niche Networks for New Entrants

How new entrant carriers may use returns to airline networks in competition is discussed. In addition to overall returns to scope and density, there are more localized returns that are based on network shape. A network shape index, which is a measure of airline network concentration based on the Herfindahl-Hirschman index, is described. Airlines have chosen many different shapes as measured by the network shape index, and new entrants tend to be shaped differently from major airlines. A model of new entrant profitability relative to the major airlines is developed. New entrants whose network shape indices are substantially different from the major airlines have niche networks, and the model indicates that niche networks are associated with higher profitability.