full employment level of national income and equilibrium level of national income: inflationary and deflationary gaps

📊 The Circular Flow of Income

Think of the economy as a big roundabout where money and goods keep circling.

Households provide labor and receive wages.

Firms use that labor to produce goods and services, selling them back to households.

The money households spend becomes the firms’ revenue, which they use to pay wages, buy raw materials, and invest.

The cycle repeats, keeping the economy moving.

Key Players

  • 🏠 Households – supply labor, demand goods.

  • 🏭 Firms – produce goods, demand labor.

  • 🏛️ Government – collects taxes, spends on public goods.

  • 🌍 Foreign Sector – exports & imports.

How the Flow Works

  1. Households supply labor to firms.

  2. Firms pay wages to households.

  3. Households spend wages on consumption goods.

  4. Firms sell goods, earning revenue.

  5. Revenue is used to pay wages, buy inputs, invest, and pay taxes.

  6. Government taxes households and firms, then spends on services.

  7. Exports bring money in; imports send money out.

📈 Full Employment Level of National Income

Full employment means every available job is filled – the economy is operating at its maximum sustainable output.

The national income at this point is called YFE (Full Employment).

The basic identity is:

\$ Y = C + I + G + (X - M) \$

where:

  • C = Consumption

  • I = Investment

  • G = Government spending

  • X - M = Net exports

Example: A Simple Economy

Suppose:

  • C = 200

  • I = 50

  • G = 80

  • X = 30, M = 20 → X - M = 10

Then:

\$ Y_{FE} = 200 + 50 + 80 + 10 = 340 \$

So the economy can produce 340 units of goods and services at full employment.

⚖️ Equilibrium Level of National Income

Equilibrium occurs when aggregate demand equals aggregate output.

If the economy is producing more than people want to buy, prices rise (inflation).

If people want to buy more than is produced, prices fall (deflation).

Inflationary Gap

Occurs when actual output (Y) > full‑employment output (YFE).

Analogy: Imagine a classroom where too many students sit in a small space – the room gets crowded and uncomfortable (prices rise).



Result: Prices go up → inflation.

Policy response: Reduce demand (e.g., higher taxes, lower government spending) or increase supply (e.g., investment in infrastructure).

Deflationary Gap

Occurs when actual output (Y) < full‑employment output (YFE).

Analogy: Think of a vending machine that has more slots than customers – goods sit idle, prices drop (deflation).



Result: Prices fall → deflation.

Policy response: Increase demand (e.g., lower taxes, higher government spending) or boost supply (e.g., subsidies for production).

Exam Tips Box

Remember:

  1. Define the gap (inflationary or deflationary) before explaining causes.

  2. Use the formula Y = C + I + G + (X - M) to show how changes in each component affect Y.

  3. Show the direction of price changes with arrows (↑ for inflation, ↓ for deflation).

  4. Link policy tools to the type of gap (e.g., contractionary policy for inflationary gap).

  5. Use clear, concise language – avoid jargon.

Quick Quiz

If the government increases spending by 20 units, what happens to the equilibrium national income?



Answer: The aggregate demand curve shifts right, increasing Y. If Y surpasses YFE, an inflationary gap may appear.

📚 Summary Table

Gap TypeY vs YFEPrice TrendPolicy Response
Inflationary GapY > YFE↑ Prices (Inflation)Contractionary (taxes ↑, G ↓)
Deflationary GapY < YFE↓ Prices (Deflation)Expansionary (taxes ↓, G ↑)