# Law of Diminishing Marginal Utility : Definition, Assumption and Exception

In this article we will study about Diminishing Marginal Utility. We will also discuss Law of Diminishing Marginal Utility : Definition, Assumption , and Exception.

## Law of Diminishing Marginal Utility

According to the Law of Diminishing Marginal Utility, Other things remaining same, this law states that when consumer is goes on consuming more and more units of a commodity, Marginal utility derived from each successive unit go on decline.

According to Marshall, “The additional benefit a person derives from a given increase of his stock of anything diminishes with the growth of the stock that he already has”.

According to Paul A. Samuelson,  “As the amount consumed of a good increases, the marginal utility of the good leads to decrease”.

Explanation

This law is easy to understand and important to understand it, it is basically concept of microeconomics. It means when a consumer consumes 2 units of a commodity and get satisfaction of 9, when he will consume 4 units get satisfaction of 8, so this law states when more and more units are consumed marginal utility tend to decline.

Assumptions of Law

1. Continuous consumption of commodity.

1. Only standard units of the commodity are consumed.

1. Utility of commodity should b measured in quantitative term like 2,4,6, etc.

1. Consumer should be rational.

1. Commodity is in homogeneous characters.

1. Taste of consumer remains same.

1. Income of consumer remains same.

1. No change in fashion.

1. Price of substitute goods doesn’t change.

Schedule and Diagram

Let we assume that when a consumer consumes more and more units of a commodity the marginal utility derived from it started decline.

 Units of Commodity Marginal Utility Total Utility 1st unit 2nd unit 3rd unit @media screen and (min-width: 1201px) { .srpjl5cea8ee819d5e { display: block; } } @media screen and (min-width: 993px) and (max-width: 1200px) { .srpjl5cea8ee819d5e { display: block; } } @media screen and (min-width: 769px) and (max-width: 992px) { .srpjl5cea8ee819d5e { display: block; } } @media screen and (min-width: 768px) and (max-width: 768px) { .srpjl5cea8ee819d5e { display: block; } } @media screen and (max-width: 767px) { .srpjl5cea8ee819d5e { display: block; } } 4th unit 5th unit 6th unit 8 6 4 2 0 2 08 14 18 20 20 18

In this figure , when the consumer consumes 1 unit he will get marginal utility of 8, when he consumes more unit 1 to 2 units marginal utility goes to 6 , MU started decline, when he consume 3 units marginal utility decreases to 4. So this diagram shows when consumer consumes more and more units marginal utility derived tends to decline.

Exceptions of Law

1. No dissimilar units are consumed.

1. No unreasonable quantity of commodity consumed.

1. No change in taste of consumer.

1. No change in time of consumption.

1.  No change in Income of the person.

So we will discuss Law of Diminishing Marginal Utility : Definition, Assumption ,and Exception. For any query comment below.