What is the result of an increase in the labor force with fixed capital?

When the labor force increases while the amount of capital remains fixed, the marginal product of labor (MPL) typically decreases. This is due to the principle of diminishing marginal returns. As more workers are added to the production process without an increase in capital, each additional worker has less capital to work with. This can lead to a situation where workers are not as productive as they would be if there were enough capital to support them adequately.

In essence, when the labor force expands in a fixed capital environment, workers may crowd each other and utilize the available capital less efficiently, thus reducing the marginal output generated by each additional worker. This reflects the negative relationship between the number of workers and the marginal product of labor when capital is held constant.

While total output may increase due to more workers contributing to production, the specific question focuses on the behavior of MPL, which clearly illustrates the diminishing returns effect in this scenario.