Ben-Gad__EC2015_Week_3_Teaching_Slides

Week 3 - The Determination of Income in the Long-run

1. Overview of Income Determination in Macroeconomics

  • Examination of long-run income determination in macroeconomic models.

  • Importance of understanding the interaction between supply and demand sides of the economy.

2. The Macroeconomic Framework

2.1 The Supply Side

  • Production Function: GDP (Y) depends on inputs like capital (K) and labor (L): [ Y = F(K, L) ]

  • Assumptions of the Neoclassical Model:

    • Perfectly competitive markets for factors of production.

    • Wages and prices adjust to clear markets.

  • Factors of Production: Labor and capital are key determinants of output.

3. Properties of the Production Function

  • Constant Returns to Scale: Outputs double with the doubling of inputs.

  • Diminishing Marginal Returns: As more of one input is added, the additional output generated decreases.

  • Mathematical Representation:

    • ( \frac{\partial F}{\partial K} > 0 );

    • ( \frac{\partial^2 F}{\partial K^2} < 0 ) for capital.

    • Similar for labor (L).

4. The Distribution of Income

  • How national income is divided between factors of production (labor vs capital).

  • Market Equilibrium: Factor prices adjust based on supply and demand in labor and capital markets.

  • Marginal Productivity Theory: Factors are compensated based on their contribution to output.

5. The Cobb-Douglas Production Function

  • Developed by Paul Douglas and Charles Cobb to quantify income distribution:

    • ( Y = K^\alpha L^{1-\alpha} ), where 0 < ( \alpha ) < 1 determines capital's share.

  • Empirical findings show that income shares have remained relatively stable over time.

6. The Demand Side of the Economy

6.1 Consumption Function

  • The economy's output is driven by consumption, which depends on disposable income.

  • Marginal Propensity to Consume (MPC): Defines how consumption changes with income.

6.2 Investment Function

  • Investment behavior is negatively related to real interest rates.

  • Government Purchases: Impact output and overall income.

7. Equilibrium and Income Determination

  • Equilibrium Output: Determined when aggregate demand equals aggregate supply.

  • Loanable Funds Market: Equilibrium adjusts interest rates based on savings and investment behaviors.

8. Key Economic Indicators**:

  • Monitoring of national accounts, such as the Balance of Payments, reveals trends over time.

  • Changes in labor share across various economies (like the U.S. and UK) and their implications.

9. Summary of Equilibrium Dynamics

  • Effects of Shifts in Demand and Supply: How changes in fiscal policy or investment demand affect overall economic equilibrium.

  • Implementation of macroeconomic policies must consider these dynamics for successful economic management.

10. Future Topics

  • Next week's focus is on the Money Market and its influence on income and liquidity.