Consumer Equilibrium, Indifference Curve, and Consumer Behaviour

Meaning of Consumer Equilibrium

Consumer equilibrium means that you are completely satisfied with the way you are spending your money. It happens when you are enjoying the utmost happiness from goods and services within your limited budget.

• You feel no regrets for the way you have spent your money.
• You are utterly confident that you cannot get more satisfaction by spending the money in some other way.
• You do not want to switch to another combination of goods and services.

For example, you have Rs 100 in your pocket.

You want to purchase chocolates and ice cream with that money.

The price of ice cream is 20, and that of a chocolate is 10.

You will buy 3 cups of ice cream and 4 chocolates. But you are unable to enjoy the 3rd cup of ice cream, and it goes to waste. With the chocolates, you feel very happy and content. You feel that you could have enjoyed two more chocolates instead. 

So, the next time, you will buy 2 cups of ice cream and 6 chocolates. You feel completely satisfied and happy with your choice. This level of satisfaction is known as "Consumer Equilibrium" in economics.

Consumer Equilibrium Definition

Consumer equilibrium is the point of maximum satisfaction where a consumer attains the highest possible utility within their limited income. It represents the situation where the consumer can purchase the optimal quantity of goods and services available at current prices, given their income level.

Conditions for a Single Product:

The consumer has a fixed amount of money to spend, and the extra satisfaction (marginal utility) from the last rupee spent equals the price of the good.

Formula: Marginal Utility (MU) = Price (P).

Conditions for Multiple Products: 

All products have equal per-rupee utility, and the satisfaction gained per rupee spent is the same across all purchased items.

If there are two goods X and Y, and the Price of each is P, then the marginal utility of good X divided by the Price of good X will be equal to the marginal utility of good Y divided by the Price of good Y

So, the Formula for Multiple Products is MUX/PX = MUY/PY

It means that the marginal utility derived from good X equals the marginal utility from good Y. 

This applies to any number of products(goods) under Consumer Equilibrium.   

Assumptions underlying Consumer's Equilibrium

The following are some of the assumptions implicit in consumer equilibrium.

• The consumer's income is given, and He has to spend within that income.
• The prices are set and stable for the time being under study.
• It is assumed that he has to choose only from various combinations of products available in the market during that particular time.
• The availability of goods and the time gap play an important role along with his income levels.

Marginal Utility is measured in units, and these units are called Utils. So, you can say that you enjoyed a marginal utility of 60 Utils from your ice cream if you ate two ice creams and their utilities were 100 utils for the first ice cream and 60 for the second one.

There are two ways of viewing marginal utility:

1. The Cardinal View (Numbers): 

You give numbers to the utility derived: 100 utils, 60 utils, 30 utils, etc. 

But many economists argue that you can not actually visualise and count the satisfaction derived using numbers. They are only assumptions.

2. The Ordinal View (Rankings):

This is the modern, realistic approach. It assumes you can not measure utility in numbers, but you can rank them.

Indifference Curve

An indifference curve is a curve formed on a graph by connecting the points of different combinations of two commodities that a consumer regards as of equal value and are giving him equal satisfaction. The consumer regards any combination on that curve as of equal value, and so he is indifferent to each of those combinations.

With a given income and the present ranges of prices, the consumer has to choose among various alternative combinations of goods and services to derive utmost satisfaction and enjoy most of those goods and services. 

The manner in which he responds and the solution that he finds at a particular level with a given combination is his equilibrium.

Indifference Curve Example

Now, let us take an example. Suppose your income is $100 and you have to purchase two goods within that income. 

Let us assume that the price of product X is $10, and that of product Y is $20. 

Now, if you want to purchase only one commodity, then you can purchase either 10 units of X or 5 units of Y. 

But you can't have only one item. You have to buy both items to maximise your satisfaction levels. So, you will try different combinations of those goods, and the results are depicted through the indifference curves in the indifference map below.

In the figure above, the X-axis represents product X and the Y-axis represents product Y. At the right-hand tip of each curve, IC stands for the indifference curve. We have drawn four indifference curves, labeled IC1, IC2, IC3, and IC4. You will notice that points on IC1, IC2, and IC3 fall within your income range. However, IC4 is completely outside your income range, as it lies beyond the price line. The price line AB is tangent to the indifference curve IC3 at point E. Therefore, point E can be considered the consumer equilibrium point, at which the consumer maximizes satisfaction by purchasing Q1 units of product X and Q2 units of product Y. Any other points on lower levels that touch the price line will yield less satisfaction. Furthermore, at those points, the consumer is not spending his full income. Points at higher levels do not touch the price line AB and so are not within his income range.

To Sum-Up,

Consumer equilibrium is the point at which the consumer maximizes satisfaction by spending his full income on those products in the most effective way. In real life, there are so many products that the buyer purchases, and it is a more complicated problem. The decision-making ability of the consumer shows his smartness and prudence in attaining consumer equilibrium.