Final answer:
Derived demand refers to the demand for inputs like labor, which is dependent on the demand for the product a firm is producing. As the demand for the product increases, the demand for labor also increases.
Step-by-step explanation:
Derived Demand
Economists describe the demand for inputs like labor as a derived demand. Since the demand for labor is MPL*P, it is dependent on the demand for the product the firm is producing. We show this by the P term in the demand for labor. An increase in demand for the firm's product drives up the product's price, which increases the firm's demand for labor. Thus, we derive the demand for labor from the demand for the firm's output.