This problem may be solved by a centralized regulator. The regulator should perform Measuring, Reporting and Verification (MRV) of the actual pollution levels, and enforce the allowances. Without effective MRV and enforcement, the value of allowances diminishes. Enforcement methods include fines and sanctions for polluters that have exceeded their allowances. Concerns include the cost of MRV and enforcement, and the risk that facilities may lie about actual emissions. The net effect of a corrupt reporting system or poorly managed or financed regulator may be a discount on emission costs, and a hidden increase in actual emissions.