Think about the demand for the three popular game consoles: XBox, PS3, and Wii. What is the effect on the demand for XBox games and the quantity of XBox games demanded if, other things remaining the same:
a. The price of an XBox falls?
b. The prices of a PS3 and a Wii fall?
c. The number of people writing and producing XBox games increases?
d. Consumers' incomes increase?
e. Programmers who write code for XBox games become more costly to hire?
f. The price of an XBox game is expected to fall?
g. A new game console comes onto the market, which is a close substitute for XBox.