Bill’s utility function is U(x, y) = xy.
Charlie’s utility function is U(x, y) = 1,000xy + 2,000.
Percy’s utility function is U(x, y) = -xy.
Fred’s utility function is U(x, y) = -1/(10 + 2xy).
George’s utility function is U(x, y) = x(y + 1,000).
Ron’s utility function is U(x, y) = 0.5xy - 10,000.
Ginny’s utility function is U(x, y) = x/y.
a. Who has the same preferences as Bill?
b. Who has the same indifference curves as Bill?
c. Explain why the answers to (a) and (b) differ.