It is possible to design a number of economic instruments for environmental policy with relatively low administrative costs, both for public authorities and the affected firms or households. For example, taxes on petroleum products are levied on a limited number of petroleum refineries and depots, and should hence be relatively simple to administer and enforce. For example, the administrative costs of the ecological tax reform in Germany are estimated to comprise only 0.13% of the additional revenues raised, according to Deutscher Bundestag (2002). This was said to be very low, for example compared to the administrative costs of the income tax in Germany.