The basic circular flow of income between households and firms

The circular flow of income model illustrates how money moves through an economy, linking national output, income, and expenditure. It shows the interactions between households, which provide resources, and firms, which produce goods and services.

Key components of the circular flow

• Households - Supply factors of production, such as labour, land, and capital, to firms.
• Firms - Use these factors to produce goods and services, which form the national output.
• National income - Payments made by firms to households for the factors of production.
• National expenditure - Spending by households on the goods and services produced by firms.

This creates a continuous cycle where:

National output = national income = national expenditure

Types of flows in the model

The model includes two distinct flows:

• Physical flow - Involves real resources, with labour, land, and capital moving from households to firms, and goods and services (output) moving from firms to households.
• Monetary flow - Involves money, with income flowing from firms to households and expenditure flowing from households to firms.

At full employment, where all willing workers have jobs at current wage rates, national income, output, and expenditure are equal to the full employment income level.

Injections into and withdrawals from the circular flow

The circular flow is not static; it is influenced by external factors that add to or remove money from the cycle. Without these, the economy would remain unchanged as long as spending matches earnings.

Injections

Injections increase the money in the circular flow and go directly to firms:

• Exports - Payments from overseas buyers for domestic goods and services.
• Investment - Spending by firms on capital goods, such as machinery or buildings.
• Government spending - Public expenditure on goods, services, or infrastructure.

Withdrawals

Withdrawals reduce the money in the circular flow and can be made by households or firms:

• Imports - Spending on foreign goods and services, which leaves the domestic economy.
• Savings - Money set aside by households or firms, not spent on goods and services.
• Taxes - Payments to the government, reducing available income for spending.

Effects on the economy

• Equilibrium - Occurs when injections equal withdrawals, keeping the economy stable.
• Injections greater than withdrawals - Leads to expenditure exceeding output, prompting firms to increase production; this raises national output, income, and expenditure.
• Withdrawals greater than injections - Results in output exceeding expenditure, causing firms to cut production; this lowers national output, income, and expenditure.

The multiplier effect of injections

An injection into the circular flow creates a chain reaction, leading to a larger overall increase in national income than the initial amount injected. This is known as the multiplier effect, where money circulates multiple times before fully leaking out.

How the multiplier effect works

• An initial injection, such as government investment, adds new income to households.
• Households spend part of this income on goods and services, creating further expenditure for firms.
• Firms then pay out some of this as income to households, and the process continues.
• At each stage, some money leaks out as withdrawals (savings, taxes, imports), reducing the amount circulating.
• The total impact on national output, income, and expenditure exceeds the original injection due to these repeated cycles.

Factors influencing the size of the multiplier

• Rate of leakages - Higher withdrawals (e.g., more spending on imports or higher taxes) cause money to leave the flow faster, resulting in a smaller multiplier effect.
• Spending patterns - If a large portion of additional income is spent domestically rather than saved or used for imports, the multiplier effect is larger.

The difference between wealth and income

While income represents money flowing through the economy, wealth is a separate concept related to accumulated resources.

Wealth

Wealth is the total value of assets owned by individuals or firms in an economy. Assets include monetary items, such as savings or cash, and physical items, such as property, vehicles, or equipment. Wealth is a stock concept, like a stored reserve of resources that are not actively circulating but could enter the flow in the future.

Key differences from income

• Flow vs. stock - Income is a continuous flow of money (e.g., wages or profits), while wealth is a static stockpile.
• Correlation between income and wealth - Higher income often leads to greater wealth, as individuals can afford more assets or save more, but they are not the same. For example, someone with high earnings might build substantial savings and investments over time.