Individual transferable quotas (ITQs) assign property rights in fisheries by granting individual fishers a tradable share of the total allowable catch (TAC). ITQs were originally proposed to enhance profitability and safety, but may also provide incentives for more conservation-minded fishing practices. Indeed, recent empirical evidence shows a reduction in the likelihood of stock collapse and a threefold increase in catches two decades after ITQ implementation. Yet these spectacular catch increases follow modest 20% reductions in reported catches. We used standard fisheries models to analyze whether these catch trends are consistent with the theory underlying conservation benefits from property rights. We find that it appears unlikely that catch increases are attributable to ITQs alone. Improved catch reporting systems are often enacted concurrent with ITQs and may plausibly explain sustained catch increases. The existence of this alternative explanation warrants caution about claims that property rights are the cause of sustainable catch gains.

JEL Classification Codes: Q22, Q58