Posted by Anjali Kaur on Oct 06, 2020

# Determination of Equilibrium Output

For the determination of Equilibrium output there are 2 approaches:

2. S-I Approach

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## Aggregate Demand (AD) – Aggregate Supply (AS) Approach

According to the modern theory of income and employment determination. In any economy, at any given time, income and employment are determined at that level where;

As shown below, equilibrium level of income (Y) is determined at the point E, where AD = AS.

Before reaching point E, Aggregate demand is more than Aggregate supply.

Beyond or after point E, Aggregate supply is more than Aggregate demand.

Now, we will learn how the economy reaches the equilibrium.

### Case 1: AD > AS

When AD > AS, this implies that Aggregate supply is less than the Aggregate demand.

So, the flow of goods and services in the economy is less as compare to the demand in the economy.

As a result, the existing stock of producer will be sold out. The producer will start producing more and will continue to increase production till the time, AS becomes equal to AD.

### Case 2: AD < AS

When AD < AS, this implies that Aggregate supply is more than the Aggregate demand.

So, the flow of goods and services in the economy exceeds there demand in the economy.

As a result, some of the goods will remain unsold. To clear the unwanted stock, the production will be reduced. AS will be decreased till the time it becomes equal to AD.

## Savings (S) – Investment (I) Approach

Under this approach, equilibrium level of income or output is determined at a point where planned savings is equal to the planned investment.

As shown below, equilibrium level of income or output is determined where S = I.

In this diagram, S is the saving curve and I is the investment curve showing autonomous investment. The equilibrium level of income is OY, which occurs at the point E, when S and I curves intersects each other.

The economy will face dis equilibrium if S > I or S < I. Let’s discuss these 2 cases:

### Case 1: Savings < Investment (S< I)

If planned savings is less than the planned investment, that is, before point E.

It means that household are consuming more and savings less than what the firm expected them to consume.

As a result, stock would fall and firms will increase the production till the time, Savings becomes equal to the Investment.

### Case 2 : Savings > Investment (S > I)

If planned savings is greater than planned investment, that is, after point E.

It means that household are not consuming as much as the firms expected them to consume.

As a result, stock increases. To clear the unwanted stock, the firm will reduce the production till, Savings and Investment becomes equal to each other.

You can read the related post on macroeconomics:

Types of Employment Equilibrium

Concept of Short-Term Equilibrium

Aggregate Supply

Aggregate Demand

Introduction To Money

Central bank and its function

Process of credit creation

Precautions while calculating the national income

Real and nominal GDP

National income

National income formula list

Income method

Expenditure method

GDP and welfare

Domestic territory and national residents

Circular flow of income

Happy Learning!

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