exchange rateJuly 22, 2026externalityJuly 22, 2026 July 22, 2026 A tax that is added to an item’s cost when it is purchased and applies to a single type of good. Related Articles: How to Solve a Highway ProblemThe Impact of High Marijuana TaxesThe Lid on the Pot IndustryThe Economic Significance of Alcohol ConsumptionThe Reason the Price of Gasoline Has That 9/10 Share