"A new celebrity endorsement, a rise in consumers disposable income, a decrease in the price of a product, and a price rise for comparable prodcts are all factors that might cause what?" A lower equilibrium price for the product A decrease in the demand for the product An increase in the supply of the product An increase in the demand for the product QUESTION 20 "The real interest rate is actually a theoretical idea. A customer cannot go to a bank and request to pay the real rate for a cat loan or receive the real rate on a certificate of deposit. Why, then, is the real interest rate usefur? It influences purchasing power. tis more easily understood. It identifies changes in the rate not caused by inflation. It reveals inflation expectations