8. (Opportunity Cost and Economic Rent) Define economic rent. In the graph below, assume that the market demand curve for labor is initially D1. a. What are the equilibrium wage rate and level of employment? What is the amount of economic rent? b. Next assume that the price of a substitute resource increases, other things constant. What happens to demand for labor? What are the new equilibrium wage rate and level of employment? What happens to the amount of economic rent? c. Suppose instead that demand for the final product drops, other things constant. Using labor demand curve D1 as your starting point, what happens to demand for labor? What are the new equilibrium wage rate and level of employment? Does the amount of economic rent change