In economics, a duty is a kind of tax, often associated with customs, a payment due to the revenue of a state, levied by force of law. It is a tax on certain items purchased abroad. [1]Properly, a duty differs from a tax in being levied on specific commodities, financial transactions, estates, etc., and not on individuals; thus it is right to talk of import duties, excise duties, death or succession duties, etc., but not of income tax as being levied on a person in proportion to his income.

http://en.wikipedia.org/wiki/Duty_(economics)

duty - porez, dažbina; carina (Rečnik bankarstva i finansija)
duty - u širem značenju svaka dažbina nametnuta od strane vlasti a u užem carina koja se naplaćuje pri uvozu ili izvozu robe (Bankarsko investicioni rečnik)

http://www.i2i.org/main/article.php?article_id=234

U vasem kontekstu: Local and state level taxes.

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Note added at 1 hr (2010-04-22 12:24:00 GMT)
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http://www3.mruni.eu/~int.economics/5nr/Davulis.pdf