Macroeconomics Final Exam Review: Key Concepts and Calculations

Introduction to Economics

What is Economics?

Economics is the study of how individuals and societies make optimal choices in the face of scarcity. It examines the allocation of limited resources to satisfy unlimited wants.

• Scarcity: The fundamental economic problem of having limited resources to meet unlimited needs.

• Optimal Choices: Decisions that maximize utility or benefit given constraints.

Macroeconomics vs. Microeconomics

Economics is divided into two main branches:

• Microeconomics: Focuses on individual agents, such as households and firms, and their decision-making.

• Macroeconomics: Studies the economy as a whole, including aggregate measures like GDP, unemployment, and inflation.

Free Rider Problem

A free rider is someone who benefits from resources, goods, or services without paying for them or contributing to their provision.

• Example: Public goods like national defense or clean air.

Positive vs. Normative Economic Analysis

• Positive Analysis: Objective, fact-based statements ("what is").

• Normative Analysis: Subjective, value-based statements ("what ought to be").

Economic Models and Empiricism

• Economic Model: A simplified representation of reality using assumptions to predict outcomes.

• Empiricism: Using data to build and test models; models are corrected if outcomes do not match reality.

Statistical Tools in Economics

Mean and Median

• Mean: The average value of a dataset.

• Median: The middle value when data is ordered.

Percentage Change

• Formula: $\frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100$

Correlation vs. Causation

• Correlation: A statistical relationship between two variables.

• Causation: One variable directly affects another.

• Positive Correlation: Both variables move in the same direction.

• Negative Correlation: Variables move in opposite directions.

Markets: Supply and Demand

Supply and Demand Curves

Supply and demand curves illustrate the relationship between price and quantity in a market.

• Equilibrium: The point where supply and demand curves intersect, indicating market price and quantity.

Law of Supply and Demand

• Law of Demand: As price decreases, quantity demanded increases.

• Law of Supply: As price increases, quantity supplied increases.

Movements vs. Shifts

• Movement: Caused by changes in price (Y-axis variable).

• Shift: Caused by changes in other factors (e.g., preferences, income, costs).

Factors Shifting Demand

• Consumer preferences

• Price of complements and substitutes

• Consumer income (normal vs. inferior goods)

• Expectations of future prices

Factors Shifting Supply

• Cost of wages, supplies, machinery

• Taxes or subsidies

• Expectations of future prices

Measuring National Production and Income

Gross Domestic Product (GDP)

GDP is the market value of newly produced goods and services within a country for a given year.

• Exclusions: Criminal activity, unpaid work, negative externalities (e.g., pollution).

Expenditure Approach to GDP

• Formula: $Y = C + I + G + NX$

• Where: C = Consumption, I = Investment, G = Government Spending, NX = Net Exports (Exports - Imports)

GDP per Capita and GDP per Worker

• GDP per Capita: Measures standard of living ($\frac{\text{GDP}}{\text{Population}}$)

• GDP per Worker: Measures productivity ($\frac{\text{GDP}}{\text{Number of Workers}}$)

Nominal vs. Real GDP

• Nominal GDP: Uses current year prices and quantities.

• Real GDP: Uses current year quantities and base year prices.

GDP Growth

• Formula: $\frac{\text{Real GDP}_{\text{current}} - \text{Real GDP}_{\text{previous}}}{\text{Real GDP}_{\text{previous}}} \times 100$

GDP Deflator

• Formula: $\frac{\text{Nominal GDP}}{\text{Real GDP}} \times 100$

• Purpose: Measures inflation in the economy.

Inflation Rate

• Formula: $\frac{\text{Price Index}_{\text{current}} - \text{Price Index}_{\text{previous}}}{\text{Price Index}_{\text{previous}}} \times 100$

Consumer Price Index (CPI) Applications

• Base Year Value: $\text{Nominal Value} / (\text{CPI}/100)$

• Nominal Value: $\text{Base Year Value} \times (\text{CPI}/100)$

Comparing GDPs Internationally

• Use exchange rates and Purchasing Power Parity (PPP) ratios.

• PPP Ratio Calculation: Compares the relative purchasing power of currencies.

Rule of 70

• Formula: $\frac{70}{\text{Percentage Growth Rate}}$

• Purpose: Estimates years to double a variable (e.g., GDP).

Compound/Exponential Growth

• Formula: $\text{Compound Growth} = \text{Initial Value} \times (1 + \text{Growth Rate})^{\text{Years}}$

Theories of Economic Growth

• Proximate Causes: Capital, labor, technology.

• Fundamental Causes: Geography, culture, institutions.

• Inclusive vs. Extractive Institutions: Inclusive institutions promote growth; extractive institutions hinder it.

Unemployment and Inflation

Types of Unemployment

• Cyclical: Due to economic downturns.

• Structural: Due to changes in industry or technology.

• Frictional: Short-term, between jobs.

Natural Rate of Unemployment & Full Employment

• Natural Rate: The sum of structural and frictional unemployment.

• Full Employment: When cyclical unemployment is zero.

Labor Market Calculations

• Labor Force: Unemployed + Employed

• Unemployment Rate (U3): $\frac{\text{Unemployed}}{\text{Labor Force}} \times 100$

• Labor Participation Rate: $\frac{\text{Labor Force}}{\text{Population} \geq 16 \text{ years}} \times 100$

Aggregate Demand and Aggregate Supply

AD/AS Model

The Aggregate Demand (AD) and Aggregate Supply (AS) model explains equilibrium output and price level in the economy.

• Equilibrium: Intersection of AD and AS curves.

• Shifts in AD: Changes in government spending, taxes, money supply.

• Shifts in AS: Changes in labor, capital, technology, natural resources.

Fiscal Multiplier

• Formula: $\frac{1}{1 - \text{MPC}}$

• Change in GDP: $\text{Change in Government Spending} \times \text{Fiscal Multiplier}$

Fiscal Policy and Government Spending

Stabilization Policy

• Goal: Stabilize the economy around full employment or Long Run Aggregate Supply (LRAS).

• Weaknesses: Inside lag, outside lag, estimation errors.

Types of Government Spending

• Discretionary: Decided annually by Congress.

• Mandatory/Entitlement: Required by law (e.g., Medicare/Medicaid).

Laffer Curve

• Tax rates beyond a certain point reduce total revenue.

Business Investment Spending

• Most volatile component of GDP; procyclical.

• Sensitive to interest rates.

• Present Value Formula: $\text{PV} = \frac{\text{FV}}{(1 + r)^t}$

Money and Banking

Characteristics of Good Money

• Store of Value

• Unit of Account

• Medium of Exchange

Types of Money

• Commodity Money

• Gold Standard

• Fiat Money

Money Supply Measures: M1 & M2

• M1: Currency + Checking + Demand Deposits + Traveler's Checks

• M2: M1 + Savings Accounts + Money Market Mutual Funds + Time Deposits

Bank Lending and Money Multiplier

• Bank Lending: $\text{Deposits} \times (1 - \text{Reserve Ratio})$

• Money Multiplier: $\frac{1}{\text{Required Reserve Ratio}}$

Summary Table: Key Formulas

Concept	Formula
Percentage Change	$\frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100$
GDP (Expenditure)	$Y = C + I + G + NX$
GDP Deflator	$\frac{\text{Nominal GDP}}{\text{Real GDP}} \times 100$
Inflation Rate	$\frac{\text{Price Index}_{\text{current}} - \text{Price Index}_{\text{previous}}}{\text{Price Index}_{\text{previous}}} \times 100$
Rule of 70	$\frac{70}{\text{Growth Rate}}$
Compound Growth	$\text{Initial Value} \times (1 + \text{Growth Rate})^{\text{Years}}$
Unemployment Rate	$\frac{\text{Unemployed}}{\text{Labor Force}} \times 100$
Labor Participation Rate	$\frac{\text{Labor Force}}{\text{Population} \geq 16}$
Fiscal Multiplier	$\frac{1}{1 - \text{MPC}}$
Present Value	$\frac{\text{Future Value}}{(1 + r)^t}$
Money Multiplier	$\frac{1}{\text{Required Reserve Ratio}}$