summerof2010 said:
Divine Miss Bee said:
XJ-0461 said:
EDIT: To clarify, what I'm basically asking is why can't American shops include VAT (or thier equivalent) in their prices?
because the total sale is what is taxed a certain percentage, not each item. does that make sense?
No. (sorry to be a dick, but I'm a math major, so I must!)
ax + ay + az = a(x + y + z)
or
(7% * 9.95) + (7% * 29.99) = 7% * 34.94
Sales tax is the same regardless of when and how you apply it.
Uh...somehow, I doubt that's the case.
(7% * 9.95) = 0.6965, which rounds up to 0.70.
(7% * 29.99) = 2.0993, which rounds up to 2.10.
So effectively, (7% * 9.95) + (7% * 29.99) = 2.80.
Whereas (7% * 34.94) = 2.4458, which rounds up to 2.45.
And 2.80 > 2.45. It should be obvious how much this effect can add up, with the result that (assuming the VAT works this way; I'm no expert on how it's calculated) the VAT ultimately makes the consumer pay considerably more because of roundoff error.
ax + ay + az = a(x + y + z) only works in theory.
EDIT: Of course, since the number you actually meant to use as the sum of 29.99 and 9.95 was 39.94, not 34.94, what really matters is (7% * 39.94), which is 2.7958, which rounds up to 2.80. So in your example, you're correct; the VAT and sales tax ultimately demand the same expenditure from the consumer. However, as the price and number of items purchased increase, so does the potential for roundoff error, so real differences can and will appear in larger purchases.