I should have mentioned J.S. Mill, too. He has his own wrinkle on it, and his own language, which was prosaic at the time, probably, but has been made famous by Darth Vader. Sales taxes cause a "disturbance" in values. (Let's say a "disturbance in the Force", where Force means the market.) Find this in Mill's Principles, Bk 5, Ch 4, "Of Taxes on commodities". This is pretty subtle, though. Mill supposes a general tax on ALL commodities. This, too, will cause a disturbance in values. It will go harder on commodities produced with less durable capital. He credits the idea to McCulloch. Mason Gaffney