Suppose that there are only two goods, books and coffee. Justine gets utility from both books and coffee, but her indifference curves between them are concave rather than convex to the origin.
a. Draw a set of indifference curves for Justine.
b. What do these particular indifference curves tell you about Justine's marginal rate of substitution between books and coffee?
c. What will Justine's utility-maximizing bundle look like?
d. Compare your answer to (b) to real-world behaviors. Does the comparison shed any light on why economists generally assume convex preferences?