Macroeconomics Chapter 8: AE, AD, AS, and the Multiplier – Step-by-Step Study Guidance

Q1. How does a fall in the domestic price level affect the Aggregate Expenditure (AE) function?

Background

Topic: Aggregate Expenditure (AE) and Price Level

This question tests your understanding of how changes in the price level influence aggregate expenditure through wealth and net export effects.

Key Terms and Concepts:

• Aggregate Expenditure (AE): The total planned spending in an economy at each income level.

• Wealth Effect: When the price level falls, the real value of money holdings rises, increasing consumption.

• Net Export Effect: A lower domestic price level makes domestic goods cheaper for foreigners, boosting exports.

Step-by-Step Guidance

1. Recognize that a fall in the domestic price level increases the real wealth of households, which tends to increase consumption spending.

2. Understand that lower domestic prices make Canadian goods more attractive to foreign buyers, increasing net exports.

3. Both effects (higher consumption and higher net exports) cause the AE function to shift upward at every income level.

4. When drawing the AE diagram, show a new AE line (AE1) above the original (AE0), keeping the slope the same (parallel shift).

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Q2. If government spending increases by $800 and the multiplier is 2.5, with a horizontal supply curve, how do you find the new equilibrium output and draw the new AD curve?

Background

Topic: Multiplier Effect and Aggregate Demand (AD) Shifts

This question tests your ability to apply the multiplier formula to changes in government spending and to interpret the effects on the AD curve and equilibrium output when the aggregate supply curve is horizontal.

Key Terms and Formulas:

• Multiplier: The ratio of the change in equilibrium output to the change in autonomous spending.

• Formula:

$\Delta Y = \text{multiplier} \times \Delta G$

• $\Delta Y$ = change in equilibrium output (real GDP)

• $\Delta G$ = change in government spending

Step-by-Step Guidance

1. Identify the change in government spending ($\Delta G = 800$) and the multiplier (2.5).

2. Calculate the total change in output using the multiplier formula: $\Delta Y = 2.5 \times 800$.

3. Find the new equilibrium output by adding the change in output to the initial output (e.g., if initial output is 5,000: $Y_1 = 5,000 + \Delta Y$).

4. Since the supply curve is horizontal, the price level remains unchanged; only output increases.

5. On the AD-AS diagram, draw the new AD curve (AD1) as a parallel shift to the right of the original (AD0), and plot the new equilibrium point at the higher output and unchanged price level.

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Q3. Which of the following causes the short-run aggregate supply (SRAS) curve to shift upward?

Background

Topic: Short-Run Aggregate Supply (SRAS) Shifts

This question tests your understanding of what factors cause the SRAS curve to shift, focusing on cost and productivity changes.

Key Terms and Concepts:

• SRAS Curve: Shows the relationship between the price level and the quantity of goods and services supplied in the short run.

• Productivity: Output per unit of input; lower productivity increases costs.

• Cost Shocks: Changes in input costs (wages, capital, etc.) can shift SRAS.

Step-by-Step Guidance

1. Recall that a decrease in labor productivity means firms produce less output with the same inputs, raising unit costs.

2. Higher unit costs cause firms to supply less at every price level, shifting the SRAS curve upward (to the left).

3. Review other options: improvements in technology, lower wage rates, or lower capital costs all reduce costs and shift SRAS downward (to the right).

4. A decrease in the price level causes movement along the SRAS, not a shift.

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Q4. For each scenario, determine whether it causes a movement along or a shift of the AD or AS curve:

Background

Topic: Movements vs. Shifts in AD-AS Model

This question tests your ability to distinguish between factors that shift the aggregate demand or supply curves and those that cause movements along them.

Key Terms and Concepts:

• Aggregate Demand (AD): Total demand for goods and services at different price levels.

• Aggregate Supply (AS): Total output firms are willing to produce at different price levels.

• Movement Along Curve: Caused by a change in the price level.

• Shift of Curve: Caused by changes in non-price factors (e.g., technology, costs, foreign demand).

Step-by-Step Guidance

1. For an increase in demand for exports, recognize this increases AD, shifting the AD curve right and causing a movement along the AS curve.

2. If AI advances reduce service-industry costs, this lowers production costs, shifting the AS curve downward/right.

3. A decrease in business confidence reduces investment (a component of AD), shifting the AD curve left and causing a movement along the AS curve.

4. Remember: demand-side changes (C, I, G, NX) shift AD; cost/productivity changes shift AS.

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Q5. How does the size of the multiplier depend on the slope of the Aggregate Supply (AS) curve?

Background

Topic: Multiplier Effect and AS Curve Slope

This question tests your understanding of how the effectiveness of fiscal policy (the multiplier) changes depending on whether the AS curve is flat or steep.

Key Terms and Concepts:

• Multiplier: Measures how much output changes in response to a change in autonomous spending.

• AS Curve Slope: Flat AS means output can rise without much price increase; steep AS means price rises more than output.

Step-by-Step Guidance

1. Identify that the multiplier is largest when the AS curve is flat (horizontal), because increases in spending translate fully into higher output.

2. As the AS curve gets steeper, increases in spending lead more to price increases than output increases, so the multiplier effect is smaller.

3. On a graph, the region where AS is flat (A–B) shows the largest multiplier; where AS is steep (D–E), the multiplier is smallest.

4. Remember: "The flatter the AS curve, the larger the multiplier; the steeper the AS curve, the smaller the multiplier."

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Q6. Comparing two economies, one with a horizontal AS curve (Economy A) and one with an upward-sloping AS curve (Economy B):

Background

Topic: Aggregate Supply Shapes and the Multiplier

This question tests your ability to compare the effects of fiscal policy and the multiplier in economies with different AS curve shapes.

Key Terms and Concepts:

• Horizontal AS Curve: Indicates constant unit costs; output is demand-determined.

• Upward-Sloping AS Curve: Indicates rising unit costs as output increases; output is partially supply-constrained.

• Multiplier: Larger when AS is flat, smaller when AS is steep.

• Wealth Effect: When price level rises, real wealth falls, partially offsetting increases in spending.

Step-by-Step Guidance

1. For Economy A (horizontal AS), recognize that unit costs are constant and output is determined by aggregate demand.

2. For Economy B (upward-sloping AS), unit costs rise as output increases, so the multiplier is smaller.

3. When autonomous expenditure increases, Economy A experiences a larger output increase than Economy B.

4. In Economy B, an increase in AD raises the price level, which reduces real wealth and partially offsets the spending increase (negative wealth effect).

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