FairTax opponents state that compliance decreases when taxes are not automatically withheld from citizens, and that massive tax evasion could result by collecting at just one point in the economic system. Compliance rates can also fall when taxed entities, rather than a third party, self-report their tax liability. For example, ordinary personal income taxes can be automatically withheld and are reported to the government by a third party. Taxes without withholding and with self-reporting, such as the FairTax, can see higher evasion rates. Economist Jane Gravelle of the Congressional Research Service found studies showing that evasion rates of sales taxes are often above 10%, even when the sales tax rate is in the single digits. Tax publications by the Organisation for Economic Co-operation and Development (OECD), IMF, and Brookings Institution have suggested that the upper limit for a sales tax is about 10% before incentives for evasion become too great to control. According to the GAO, 80% of state tax officials opposed a national sales tax as an intrusion on their tax base. Opponents also raise concerns of legal tax avoidance by spending and consuming outside of the U.S. (imported goods would be subject to collection by the U.S. Customs and Border Protection).