5"A tax whose tax base is a physical unit (or a proxy of it) of something that has a proven, specific negative impact on the environment.",OECD/EC guideline (2001).
6"This database defines environmentally related taxes as any compulsory, unrequited payment to general government levied on tax-bases deemed to be of particular envirotunental relevance. Taxes unrequited in the sense that benefits provided by government to taxpayers are not normally in proportion to their payments.", OECD, Environmentally Related Taxes database.
7在OECD数据库中,环境税也包括各种收费(Fee and Charge). OECD. ThePolitical Economy of Environmentally Related Taxes, OECD Publications, 2006.
