Chapter 10: Financial Markets and Real GDP

Supply and Demand for Loanable Funds

The market for loanable funds determines the equilibrium interest rate and the quantity of funds lent and borrowed in the economy.

• Supply Curve Shifts: The supply of loanable funds increases with higher savings rates, government budget surpluses, and positive changes in consumer confidence. It decreases with lower savings or budget deficits.

• Demand Curve Shifts: The demand for loanable funds increases with higher expected returns on investment, business optimism, and government borrowing. It decreases with lower investment opportunities or pessimism.

• Example: If the government runs a deficit, the supply of loanable funds shifts left, raising interest rates.

Calculating Growth Rates and the Rule of 70

Growth rates measure how quickly an economic variable, such as real GDP, increases over time.

• Growth Rate Formula:

• Rule of 70: Estimates the number of years required for a variable to double, given its annual growth rate.

• Rule of 70 Formula:

• Example: If GDP grows at 2% per year, it will double in approximately 35 years ().

Chapter 11: Economic Growth and Technological Change

Determinants of Long-Run Economic Growth

Long-run economic growth is driven by increases in resources, improvements in technology, and institutional factors.

• Key Determinants: Physical capital, human capital, technological progress, and sound institutions.

• Example: Investment in education increases human capital, boosting productivity and growth.

Per-Worker Production Function

The per-worker production function shows the relationship between output per worker and capital per worker.

• Movement Along the Curve: Occurs when capital per worker changes.

• Shift of the Curve: Caused by technological change or improvements in efficiency.

Technological Change and New Growth Theory

Technological change is a key driver of sustained economic growth, as described by new growth theory.

• Components: Innovation, research and development, and knowledge spillovers.

• Policies: Support for education, R&D, and intellectual property rights foster technological change.

• Example: Government grants for research can accelerate technological progress.

Convergence Theory

Convergence theory predicts that poorer economies will grow faster than richer ones, eventually catching up in terms of income per capita.

• Prediction: Countries with lower initial GDP per capita tend to experience higher growth rates.

• Failures in Low-Income Countries: Poor institutions, lack of infrastructure, and inadequate education can hinder convergence.

• Policies: Institutional reforms, investment in infrastructure, and education can address these failures.

Chapter 12: Aggregate Expenditure Model

Components of Aggregate Expenditure

The aggregate expenditure model explains how total spending determines output and income in the short run.

• Components: Consumption (C), Investment (I), Government Spending (G), and Net Exports (NX).

• Formula:

Macroeconomic Equilibrium in the AE Model

Equilibrium occurs when aggregate expenditure equals total output (real GDP).

• Equilibrium Condition:

• Disequilibrium: If , inventories fall and output rises; if , inventories rise and output falls.

Consumption Function, MPC, and MPS

The consumption function relates consumption to disposable income.

• Consumption Function: where is autonomous consumption, is the marginal propensity to consume (MPC), and is disposable income.

• MPC (Marginal Propensity to Consume): Fraction of additional income spent on consumption.

• MPS (Marginal Propensity to Save): Fraction of additional income saved.

• Example: If MPC = 0.8, then MPS = 0.2.

Representing Investment, Government Spending, and Net Exports

These components are typically shown as autonomous (not dependent on income) in the AE model.

• Investment (I): Spending by firms on capital goods.

• Government Spending (G): Purchases of goods and services by the government.

• Net Exports (NX): Exports minus imports.

Graphing Macroeconomic Equilibrium and Disequilibrium

Equilibrium is found where the AE line intersects the 45-degree line (where ).

• Expansion: Output increases as AE rises above equilibrium.

• Recession: Output falls as AE drops below equilibrium.

The Multiplier Effect

The multiplier measures how a change in autonomous spending leads to a larger change in equilibrium output.

• Multiplier Formula:

• Example: If MPC = 0.75, multiplier = 4.

Chapter 13: Aggregate Demand and Aggregate Supply (AD-AS Model)

Aggregate Demand Curve

The aggregate demand (AD) curve shows the relationship between the price level and the quantity of real GDP demanded.

• Negative Slope: Due to the wealth effect, interest rate effect, and international trade effect.

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

• Shifts: Caused by changes in consumption, investment, government spending, or net exports.

Short-Run Aggregate Supply (SRAS)

The SRAS curve shows the relationship between the price level and the quantity of goods and services firms are willing to produce in the short run.

• Positive Slope: As prices rise, firms increase output due to higher profits.

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

• Shifts: Caused by changes in input prices, technology, or expectations.

Long-Run Aggregate Supply (LRAS)

The LRAS curve is vertical, reflecting the economy's potential output at full employment.

• Vertical Line: Indicates that in the long run, output is determined by resources and technology, not the price level.

• Shifts: Caused by changes in labor, capital, or technology.

Macroeconomic Equilibrium in the AD-AS Model

Equilibrium occurs where AD intersects SRAS and LRAS.

• Short-Run Equilibrium: Determines actual output and price level.

• Long-Run Changes: Expansion or recession can be graphed as shifts in AD or SRAS.