are then used to pay for the costs of treating illness caused by alcohol use disorder. Similar taxes may exist on tobacco, pornography, etc., and they may be collectively referred to as "sin taxes". A carbon tax is a tax on the consumption of carbon-based non-renewable fuels, such as petrol, diesel-fuel, jet fuels, and natural gas. The object is to reduce the release of carbon into the atmosphere. In the United Kingdom, vehicle excise duty is an annual tax on vehicle ownership. Tariff An import or export tariff (also called customs duty or impost) is a charge for the movement of goods through a political border. Tariffs discourage trade, and they may be used by governments to protect domestic industries. A proportion of tariff revenues is often hypothecated to pay the government to maintain a navy or border police. The classic ways of cheating a tariff are smuggling or declaring a false value of goods. Tax, tariff and trade rules in modern times are usually set together because of their common impact on industrial policy, investment policy, and agricultural policy. A trade bloc is a group of allied countries agreeing to minimize or eliminate tariffs against trade with each other, and possibly to impose protective tariffs on imports from outside the bloc. A customs union has a common external tariff, and the participating countries share the revenues from tariffs on goods entering the customs union. In some societies, tariffs also could be imposed by local authorities on the movement of goods between regions (or via specific internal gateways). A notable example is the likin, which became an important revenue source for local governments in the late Qing China. Other License fees Occupational taxes or license fees may be imposed on businesses or individuals engaged in certain businesses. Many jurisdictions impose a tax on vehicles. Poll A poll tax, also called a per capita tax, or capitation tax, is a tax that levies a set amount per individual. It is an example of the concept of fixed tax. One of the earliest taxes mentioned in the Bible of a half-shekel per annum from each adult Jew (Ex. 30:11–16) was a form of the poll tax. Poll taxes are administratively cheap because they are easy to compute and collect and difficult to cheat. Economists have considered poll taxes economically efficient because people are presumed to be in fixed supply and poll taxes,