Law Of Diminishing Return

Law of diminishing marginal explains that when more and more units of variable inputs are employed on a given quantity of fixed inputs, the total output may initially increases at increasing rate, then at constant rate, but it will eventually increase at diminishing rate.

So,Some of the definitions that is given by some economists are:

According to G.Stigler," As equal increments of one input are added, the inputs of other productive services being held constant, beyond a certain point the resulting increments of product will decrease ,i.e; the marginal product will diminish."

According to F.Benhan,"As the proportion of one factor in a combination of factors is increased, after a point, first the marginal and then the average product of that factor will diminish."

So, basically there are 3 stages of diminishing return:
1. Total product and Average product increases, Marginal product is first increasing and then
    decreasing.
2. Total product is increasing, Average product and Marginal product both decreases.
3. Total product is diminishing, average product is decreasing and Marginal product is negative.