Property rights and the protection of global marine resources

Managing global marine resources by assigning property rights could align economic and conservation incentives, but only if unauthorized resource use is deterred. Exclusive Economic Zones (EEZs) are country-level property rights to marine resources, covering approximately 39% of the ocean's surface and accounting for more than 95% of global marine fish catch. However, EEZs might not be respected by unauthorized resource users because the cost of monitoring and enforcing such large areas may be prohibitive. Here we provide the first evidence that EEZs are in fact respected by unauthorized resource users. Using global, high-resolution fishing effort datasets and the ecologically arbitrary boundaries between EEZs and the high seas, we find that unauthorized foreign fishing is 81% lower just inside EEZs compared to just outside. Consistent with the high cost of enforcing EEZ boundaries, this deterrence effect is concentrated in EEZs that are most valuable near their boundaries. Our results suggest that property rights institutions can enable effective governance of global marine resource use.