Aggregate Demand and Supply Model Notes

Overview of Aggregate Demand and Aggregate Supply Model

  • The aggregate demand and supply model consists of three curves:
    • Aggregate Demand Curve (AD)
    • Long Run Aggregate Supply Curve (LRAS)
    • Short Run Aggregate Supply Curve (SRAS)
  • This model helps us understand the causes and effects of economic disturbances, such as recessions and booms.

Key Equations and Concepts

  • Equation for Money Supply Relationship:

    • m×d=p×yrm \times d = p \times y_r
    • Where:
    • mm = money supply
    • dd = velocity of money
    • pp = price level
    • yry_r = real GDP growth rate

  • Approximation of Growth Rates:

    • If growth rate of m\text{growth rate of } m = 10% -> 1.11.1
    • If growth rate of v\text{growth rate of } v = 5% -> 1.051.05
    • If inflation rate=8\text{inflation rate} = 8%, we get:
    • Growth equation: 10 ext{%} + 5 ext{%} = 8 ext{%} + y_r
    • Solving for yry_r gives:
      • y_r = 15 ext{%} - 8 ext{%} = 7 ext{%}

Aggregate Demand Curve Analysis

  • The aggregate demand curve shows combinations of inflation (p) and real growth (y_r) consistent with a specified rate of spending growth (m + d).

  • Implications of Growth Rates:

    • If m+dm + d is set at 5%, the corresponding combinations of inflation and real GDP growth can be plotted.
    • For instance:
    • If \text{inflation rate is } 5 ext{%}, then yry_r must be 0 ext{%}.
    • If \text{inflation rate is } 2 ext{%}, then yry_r must be 3 ext{%}.

Long Run Aggregate Supply Curve (LRAS)

  • The LRAS is a vertical line indicating the economy's potential growth rate based on factors like labor, capital, and productivity.
  • Independent of inflation, the long run model posits that increases in the money supply do not affect the real economy - referred to as "money neutrality".

Real Shocks and Their Effects

  • Real shocks can lead to negative effects on productivity, shifting the LRAS to the left:
    • Examples of negative shocks: wars, weather events, regulations, strikes, oil price increases.
    • Results in increased inflation and decreased growth rates.
  • Conversely, positive shocks (like favorable weather or technological advancements) shift LRAS to the right, indicating improved productivity and lower inflation.

Calculation Implications

  • The relationship between inflation, GDP growth, and aggregate demand can illustrate economic conditions:
    • If recession occurs and the growth rate drops to zero, inflation tends to rise, while GDP contracts, revealing the complexity of economic fluctuations.
  • Government policies influencing spending (like adjusting taxes) can also impact the demand curve — shifts in AD lead to varying inflation and growth rates.

Practical Applications

  • Using the AD-AS Model
    • When analyzing different economic scenarios, understanding this model provides insights into inflationary pressures and growth expectations.
    • It allows policymakers to gauge the impacts of financial strategies on economic performance.
    • Understanding the balance between aggregate demand and long run supply helps with forecasting economic conditions and avoiding potential recessions or inflations.

Conclusion

  • The Aggregate Demand and Supply model serves as a foundational framework for macroeconomic analysis, helping to comprehend various phenomena and the interrelation between growth, inflation, and real economic shocks.