Unit 4: Business Cycle

1. Concept of Business Cycle

A business cycle (or trade cycle) consists of four distinct phases that an economy passes through over time.

• Expansion (Boom): Characterized by rising GDP, high employment, and increasing consumer spending.
• Peak: The highest point of economic activity before a downturn.
• Contraction (Recession): A period of declining economic activity, falling demand, and rising unemployment.
• Trough (Depression): The lowest point of the cycle where economic activity bottoms out.

2. Multiplier and Accelerator Interaction

Economic fluctuations are often explained through the interaction between the Multiplier and the Accelerator.

The Multiplier

The Multiplier shows how an initial change in investment leads to a more than proportionate change in national income. It depends on the Marginal Propensity to Consume (MPC).

The Accelerator

The Accelerator Principle suggests that changes in the level of income lead to changes in the level of investment. Specifically, induced investment is a function of the rate of change in output.

The Interaction

The interaction creates a self-reinforcing cycle. An increase in investment raises income (multiplier effect), which then leads to further increases in investment (accelerator effect), driving the expansion phase.

3. Hawtrey's Monetary Theory of Business Cycles

R.G. Hawtrey argued that the business cycle is a purely monetary phenomenon.

• Mechanism: Fluctuations are caused by changes in the flow of money and credit.
• Role of Banks: When banks lower interest rates and expand credit, merchants increase their stocks, leading to increased production and income (Expansion).
• Turning Point: Eventually, banks run out of reserves and contract credit, leading to a fall in demand and prices (Contraction).

4. Hicks-Samuelson Business Cycle Model

This model combines the multiplier and accelerator into a unified mathematical framework to explain the cyclical nature of growth.

Key Components:

• Samuelson's Model: Focuses on how different values of the MPC and the accelerator coefficient (beta) determine whether the economy converges to equilibrium or enters explosive cycles.
• Hicks's Model: Introduces the concept of "Ceilings" (full employment limit) and "Floors" (minimum autonomous investment) to explain why cycles turn around and stay bounded.

5. Measures to Prevent Business Cycle

Governments and central banks use policies to stabilize the economy and minimize the intensity of these fluctuations.

• Monetary Measures: Controlling credit through bank rates, open market operations, and varying reserve ratios.
• Fiscal Measures: Using counter-cyclical spending and taxation. During a recession, the government increases spending and cuts taxes to stimulate demand.
• Automatic Stabilizers: Mechanisms like progressive income taxes and unemployment benefits that automatically counteract economic trends without new legislation.