Answer:
A firm will employ an additional unit of labor as long as the employment of labor adds more to the firm's revenue than it does to the firm's cost. This means that the firm will continue to hire additional labor as long as the revenue generated by the additional labor is greater than the cost of employing that labor. The firm will stop hiring additional labor when the cost of employing an additional unit of labor exceeds the revenue it generates.
Step-by-step explanation: