Quotas or permits are frequently used in the management of renewable resources and emissions. However, in many industries there is concern about the basic e ectiveness of quotas due to non-compliance. We develop an enforcement model of a quota-regulated resource and focus on a situation with signi cant non-compliance and exogenous constraints on nes and enforcement budget. We propose a new enforcement system based on self-reporting of excess extraction and explicit di erentiation of inspection rates based on compliance history. In particular, we use state-dependent enforcement to induce rms to self-report excess extraction. We show that such system increases the e ectiveness of quota management by allowing the regulator to implement a wider range of aggregate extraction targets than under traditional enforcement, while ensuring an ecient allocation of aggregate extraction. In addition, inspection costs can be reduced without reductions in welfare.