Rafael wrote:
It does not follow that just because a good's price changes, that a substitute or complementary good will react in price only through the substitute or complementary relationship.
Exactly my point. The Big Mac price can jump around all over the place due to any number of factors, including such things as advertising campaigns, a shortage of special sauce, a change to the burger, or increased demand due to starting up McCafe. There's no way to correlate one product to the market as a whole. So, if all burgers increased in price by 20%, a case could possibly be made. But, if you're looking at one item, there's so many variables as to make the extrapolation to the market complete nonsense.