Since the beginning of this century, there has been a significant increase in the price of corn-based ethanol.

a. A key input in the production of corn-based ethanol is corn. Use an appropriate diagram to explain what has likely occurred in the market for corn if the supply curve has not shifted.

b. In light of your answer to part (a), explain why many hog farmers, who in the past used corn as the main feed input in hog production, have switched to cookies, licorice, cheese curls, candy bars, and other human snack foods instead of corn as food for their hogs.