law of diminishing marginal returns

The law of diminishing marginal returns states that as the quantity of additional inputs increases, the marginal output of that additional input will eventually decrease. This is due to the fact that, with each additional input, the total output of the additional input will eventually become less effective as the other inputs are becoming less productive. For instance, in a factory, if additional employees are continually added to a production line, no matter how efficient they are, eventually their output will reduce as they become increasingly saturated with work and are unable to keep up with their peers.