The extra amount of output a firm can generate by adding one more unit of labor is called the product of labor. (Insert a single word.)

The extra amount of output a firm can generate by adding one more unit of labor is called the marginal product of labor.

The marginal product of labor (MPL) is an important concept in economics that helps firms determine the value of adding additional workers. It reflects the change in total output resulting from the employment of one additional unit of labor, holding other inputs constant. This principle is crucial in understanding production functions and the efficiency of workforce allocation. Essentially, as firms assess their labor needs, the MPL can help them optimize labor usage, thereby increasing productivity and profitability. The concept also ties into the law of diminishing returns, which states that after a certain point, the addition of input factors, like labor, will yield progressively smaller increases in output.