I feel like Meth is a whole new product altogether, it is harder on the brain and seems to have more long term effects. Maybe heroin or coke is a better substitute for crack.
Also, if you believe in Giffen goods, you may be convinced that text books fall into that category. So, while text book prices and class enrollment may hypothetically be complementary, there may be little decrease in demand after text book prices increase (because students need them either way). There may however be an inverse relationship between text book prices and the amount of beer sold on campus
Wait, what were we talking about again? I got distracted by the really colourful and clear notes....
Razors don't shave people. People shave people!
There are three critical types of moments in life: Times when we should use opportunity to be enamoured with finer details, and times we should ignore the minutia.