Changes in Aggregate Demand Curve

1. Overview of Aggregate Demand (AD)

• Aggregate demand refers to the total demand for real GDP within an economy at a given overall price level and in a given period.
• The components that influence aggregate demand include:
  • Consumption
  • Gross Investment
  • Government Purchases (g)
  • Net Exports (NX)

2. Government Purchases (g)

• Increase in Government Spending:

  • When the government increases spending on infrastructure (e.g., highways, airports), it directly increases aggregate demand for real GDP.
  • Graphical Representation:
  • This is represented as a rightward shift of the aggregate demand curve from AD to AD1.

• Decrease in Government Spending:

  • Conversely, if government purchases are reduced, this leads to a decrease in aggregate demand for real output.
  • Graphical Representation:
  • This reduction shifts the aggregate demand curve to the left from AD to AD2.

3. Net Exports (NX)

• Determinants of Net Exports:
  • The two main determinants of net exports are:
  • Exchange Rates
  • National Income Levels

A. Exchange Rates

• Appreciation of the US Dollar:

  • If the purchasing power of the US Dollar increases relative to other currencies (appreciation), foreign goods and services become cheaper for US consumers.
  • This results in:
  • An increase in imports from foreign countries.
  • A decrease in US goods and services' attractiveness to foreign consumers.
  • Thus, exports fall, leading to a net decrease in net exports.
  • Graphical Representation:
  • The decrease in net exports is represented by a leftward shift of the aggregate demand curve from AD to AD2.

• Depreciation of the US Dollar:

  • If the purchasing power of the dollar decreases (depreciation), US goods and services become cheaper for foreign consumers, and:
  • Exports increase.
  • Imports decrease.
  • This results in an increase in net exports.

B. National Income Levels

• Impact of Foreign Incomes:

  • If incomes in foreign countries rise, those countries may import more goods and services from the US, increasing US exports and net exports.
  • Conversely, if foreign incomes fall, US exports decline, leading to lower net exports.

• Impact of US Incomes:

  • Higher incomes in the US typically lead to increased demand for imported goods, which reduces net exports.
  • Conversely, a decrease in US incomes reduces demand for imports, leading to an increase in net exports.

4. Examples of Net Exports Impacting Aggregate Demand

• Case Study: Foreign Airline Purchases

  • If Asian airlines increase purchases of airplanes from the US due to higher incomes, this leads to:
  • An increase in US exports.
  • An increase in net exports.
  • A resulting rightward shift of the aggregate demand curve from AD to AD1.

• Case Study: Economic Recession in Asia

  • If Asian economies experience a recession resulting in falling incomes, this leads to:
  • A decrease in purchases of US airplanes.
  • A decrease in net exports.
  • A resulting leftward shift of the aggregate demand curve from AD to AD2.

5. Conclusion

• Changes in government purchases and net exports have a direct and significant impact on the aggregate demand for real GDP.
• Understanding these shifts is crucial for evaluating the influence of government spending and international trade on the economy.