New research in fisheries economics addresses incentives across many margins. These margins include within-season effects, incentives to harvest different ages and sizes of fish, responses to ecological disturbances, spatial choices, and multispecies interactions. Even developments in global seafood markets are relevant for understanding contemporary fisheries management. What connects this diverse literature is the attempt to align incentives of harvesters with the objectives of optimal management and reflections on when delineating policy instruments along particular margins is worthwhile. This theme echoes the older fisheries bioeconomic literature that first identified the commons problem and proposed solutions to it using an elegant but now principally metaphorical model of a single stock.