Suppose that Joey has classical bow-shaped indifference curves (convex) that do not intersect the axes for two goods X and Y. Draw an indifference curve and a budget line for Joey showing an equilibrium consumption bundle and label it A. Assume that the price of good Y increases. Carefully sketch out the change in the equilibrium bundle, indicating the income and substitution effects, assuming that:

a. Y is a normal good.

b. Y is an inferior good, but not a Giffen good.

c. Y is a Giffen good.

d. Assume now that the optimal consumption bundles on both the original budget line and the new budget line include 20 units of Y (Joey kept buying 20 units of Y even after the price of Y increased). Can you determine if Y is a normal or inferior good? What about good X? Explain.