6.5
The marginal product of the variable input labor is MPL. It is the change in total product from adding labor while keeping capital, such as the number of ovens, constant.
Consider a bakery producing bread. One baker produces 30 loaves of bread a day. With the addition of another baker, the daily output rises to 75. Here, the MPL is 45.
In the initial stage, the addition of a baker significantly increases the MPL. For example, with the addition of the second baker, the output increases by 45 units per day. This stage of increasing MPL is called the first stage or the stage of increasing marginal returns.
After a certain point, the MPL starts to decline. For example, with the addition of the third baker, the output increases by 30 units per day. The decline in MPL represents the second stage or the stage of diminishing marginal returns.
Eventually, the MPL becomes negative. This is called the third stage or the stage of negative marginal returns.
The rate at which the MPL changes is important to understand the stages of production.
The marginal product (MP) of a variable input measures the additional output produced by adding one more unit of that input, holding all other inputs…
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