Study Notes on GDP and the Macroeconomy
From Microeconomics to Macroeconomics
Definitions
Microeconomics:
Focuses on individual income, output, and spending.
Examples include: Your individual income, Output produced by your business, Your spending, or that of family/company.
Macroeconomics:
Focuses on national totals.
Covers: Total income in the whole country, Total output produced by all businesses, Total spending across all people, businesses, and the government.
The Circular Flow of Income
Key Concept: Businesses and households interact in markets for inputs and outputs.
Flow of resources matches a flow of money.
All economic activities yield equal values of total income, total output, and total spending, which determine the economy's GDP.
GDP Defined
GDP Characteristics
Defined as the market value of all final goods and services produced within a country in a year.
Market Value: Value each product at its market price.
Final Goods and Services:
Only includes final goods, excluding intermediate goods.
Omits resale of previously produced goods.
Includes all goods produced within the United States, even by foreign businesses, but excludes those produced overseas by American businesses.
Measurement:
Add up the flow of output over a year.
GDP Measures Total Spending
Key Insights
Total Spending: GDP equals total spending on final goods, encapsulating the value created at earlier production stages.
The important transaction occurs when the final user buys a product (e.g., a couch at John Lewis).
For example, the total spending in this case is $1,500 for the final good (the couch).
GDP and Inventories
Inventory Impact
Goods Counted: GDP measures production in the year they are made, regardless of the sales year.
New inventories (unsold goods produced) are included in GDP as they represent part of production.
When goods are sold, there is a decrease in inventories and an increase in final sales, ensuring that GDP reflects these transactions accurately.
Components of GDP
Breakdown of Components
GDP Calculation: GDP is the sum of the following components:
Consumption
Investment (including inventories)
Government Purchases
Net Exports
This equation functions as an identity and is always true, defining GDP comprehensively.
GDP as Total Output
Production Perspective
Definition: GDP equals total output, which can be viewed as the sum of value added at each stage of production.
Value Added Concept:
Value added at a stage is calculated as:
\text{Value Added} = \text{Total Sales} - \text{Cost of Intermediate Goods and Services}
This perspective allows for GDP calculation by aggregating total output across all businesses.
GDP Measures Total Income
Income Perspective
Total Income Definition: GDP equals the sum of all income, including total wages and total profits.
Breakdown example using three firms:
Revenue examples from each firm illustrate contributions to GDP.
Taxes and Capital Gains: Capital gains are NOT counted as new income because they involve resale rather than productive activity.
Wages and Profits Breakdown:
Total wages: $1,000
Total profits: $500
Total income from the example = $1,500.
Labour Share of Income
Stability and Impact
Labour Share of Income: Represents the portion of total income going to workers via wages, salaries, pensions, and benefits.
Capital Share: Refers to total income going to capital owners (often concentrated among the wealthy).
Trend: The labour share in the UK has remained stable over the past twenty years.
Recap: Perspectives on GDP
Key Definitions and Insights
Definition Recap: GDP is "the market value of all final goods and services produced within a country in a year."
Insights: GDP represents total spending, total output, and total income.
Practical Implication: GDP can be measured by aggregating total spending, total output, or total income, reflecting its multifaceted nature.