Source: EC 290 Lecture Notes, Class 3
Difficulty: Introductory | Prerequisites: Introduction to Macroeconomics (EC 290 Ch. 1 notes).
Before you can analyse an economy, you need to measure it. This module introduces GDP, the single most important number in macroeconomics, and the three equivalent ways to calculate it: by what is produced (product approach), by what people earn (income approach), and by what is spent (expenditure approach). You will also learn the difference between GDP and GNP, what GDP deliberately leaves out, and how national income accounting ties the whole economy together. This material is the measurement foundation for everything that follows in the course.
GDP measures the market value of all final goods and services newly produced within a country during a fixed period. There are three approaches to measuring it (product, income, expenditure), and in theory they all yield the same number. GDP counts only new, final production within national borders, while GNP counts production by a nation's own factors of production wherever they are in the world.
Gross domestic product (GDP)
The market value of final goods and services newly produced within a nation during a fixed period (usually a quarter or a year).
Think of it as the total size of the economy, measured by everything that was made and sold within the country's borders.
Gross national product (GNP) / Gross national income (GNI)
The market value of final goods and services newly produced by domestic factors of production (capital and labour), regardless of where in the world that production occurs.
In simple terms, GDP counts what is made inside the country; GNP counts what is made by the country's people and capital, even abroad.
Net factor payments from abroad (NFP)
Income paid to domestic factors of production by the rest of the world, minus income paid to foreign factors of production by the domestic economy. The formula: GDP + NFP = GNP.
Think of it as the net income flowing in from Canadian-owned operations abroad, minus the income flowing out to foreign-owned operations in Canada.
Value added
The value of a firm's output minus the value of the intermediate goods it used in production.
In simple terms, each firm's unique contribution to the final product. Summing value added across all firms avoids double-counting.
Final goods
Goods and services purchased by their ultimate users. Capital goods and inventory investment are treated as final goods.
Think of it as the finished product that no one else will resell or process further.
Intermediate goods
Goods used up in the production of other goods. They are excluded from GDP to avoid double-counting.
In simple terms, the ingredients that get folded into something else before reaching the end buyer.
Product approach
Measures GDP as the total value added across all firms in the economy.
In simple terms, add up each firm's contribution without counting any input twice.
Income approach
Measures GDP by summing all the incomes earned by the producers of output: wages, profits, rents, and interest.
Think of it as asking "where did the money go?" after everything was produced.
Expenditure approach
Measures GDP by summing all spending on final goods and services: Y = C + I + G + NX.
Think of it as asking "who bought everything that was produced?"
Compensation of employees
Total remuneration, in cash or in kind, payable by an enterprise to an employee in return for work done.
In simple terms, all wages, salaries, and benefits combined.
Gross operating surplus
Income earned from the production of goods and services that is paid to the owners of incorporated companies (corporations, governments, households, non-profit institutions). Takes the form of dividends, interest, and profits.
Think of it as the corporate profit line in the national accounts.
Gross mixed income
Income paid to unincorporated enterprises (sole proprietors, partnerships).
In simple terms, the earnings of small business owners who are both the worker and the boss, so their income mixes wages and profit.
Taxes less subsidies on production
Taxes (minus subsidies received) that companies pay on the use of labour, machinery, buildings, or other assets used in production. Examples include CPP contributions.
Think of it as the cost of doing business that flows to the government rather than to workers or owners.
Taxes less subsidies on products and imports
Taxes payable after a product is produced and sold in Canada or imported from abroad, net of subsidies (e.g. a subsidy for upgrading to an energy-efficient furnace).
In simple terms, sales taxes and tariffs minus government rebates on specific products.
In theory, all three approaches yield the same number (in practice, small discrepancies arise from incomplete or misreported data).
1. Product approach (value added)
Measures GDP as the sum of value added at each stage of production
Value added = a firm's output minus the cost of its intermediate inputs
Formula illustration: (V1) + (V2 - V1) + (V3 - V4) = V3
The reason GDP counts only final products is to avoid double-counting: if you added up the full sales price at every stage, you would count the same materials multiple times
Capital goods and inventory investment are treated as final goods
GDP excludes goods produced in previous periods (used goods are not new production)
2. Income approach
Measures GDP by adding up all incomes earned in production:
Compensation of employees (wages, salaries, benefits)
Gross operating surplus (profits, dividends, interest going to incorporated companies)
Gross mixed income (earnings of unincorporated enterprises)
Taxes less subsidies on production (e.g. CPP contributions)
Taxes less subsidies on products and imports (e.g. sales taxes minus product subsidies)
3. Expenditure approach
Measures GDP by adding up all spending on final goods and services
The expenditure identity: Y = C + I + G + NX
Y = GDP
C = consumption (household spending on goods and services)
I = investment (business spending on capital, residential construction, inventory changes)
G = government purchases of goods and services
NX = net exports (exports minus imports)
GDP measures production within national borders, regardless of who owns the factors of production
GNP measures production by domestically owned factors of production, regardless of where in the world that production happens
The link: GDP + NFP = GNP
Examples:
A Scotiabank branch operating in Mexico City earns operating surplus that counts as a positive in Canadian GNP but does not appear in Canadian GDP (it is in Mexico's GDP)
A Toyota plant operating in Canada earns operating surplus that counts in Canadian GDP but not Canadian GNP (it is in Japan's GNP)
For most large developed economies, GDP and GNP are close in value. The distinction matters more for countries with large inflows or outflows of foreign investment.
Home production:
Activities like housework, childcare, and volunteer work are not sold in markets and therefore have no market price
A home production activity is something you would pay someone else to do if you did not do it yourself
Estimated at roughly 20% of the economy's total value; in the U.S., home production is estimated at 14% to 17% of GDP
Excluded from GDP due to the lack of reliable data
The underground economy:
Includes both illegal activities and legal activities hidden from the government (e.g. cash-in-hand payments to avoid tax)
Estimated at around 2.7% of GDP in Canada, measured by tracking cash flow in the economy
Used goods and existing assets:
Sales of used houses or exchanges of existing stocks are not counted in GDP, because they are not new production
Capital gains are also excluded from GDP income measures
Research has found a strong inverse correlation between the statistical discrepancy (output minus income) and capital gains during stock or housing bubbles, suggesting some capital gains get misclassified as income in the national accounts
Government services:
Government output has no market price (it is not sold competitively), so it is valued at cost of production, primarily the wages of government employees
This is a practical solution, but it means improvements in the quality of government services are difficult to measure
Y = C + I + G + NX
C (Consumption): Spending by households on goods and services. As noted in the Ch. 1 material, consumption is roughly 60% of Canadian GDP and tends to be smooth over time
I (Investment): Business fixed investment (machinery, equipment), residential investment (new housing construction, remodelling, brokers' fees), and changes in inventories. Much more volatile than consumption
G (Government purchases): Spending by all levels of government on goods and services. About 20% of GDP. Does not include transfer payments (those appear in consumption when the recipients spend them)
NX (Net exports): Exports minus imports. When a country imports more than it exports, NX is negative
Housing enters GDP through two channels:
Residential investment: construction of new homes (single-family and multifamily), remodelling, manufactured homes, home inspections, insurance, and brokers' fees
Consumption of housing services: gross rents and utilities paid by renters, plus owners' imputed rents and utility payments (the value of living in a home you own, as if you were renting it to yourself)
Used house sales are not counted in GDP because they do not represent new production.
National income accounting is how governments, central banks, and international organisations keep score. When Statistics Canada reports quarterly GDP growth, it is using exactly these frameworks. The distinction between GDP and GNP matters for any country with significant foreign direct investment: Canada's GDP includes the output of Toyota plants in Ontario, but those profits ultimately flow to Japan and show up in Japan's GNP. Understanding how government services are valued (at cost) explains why public-sector productivity is so difficult to measure and why GDP can understate improvements in public services.
Students often think GDP measures everything of economic value. It does not. Home production, the underground economy, and unpaid care work are all excluded
Students sometimes confuse GDP with GNP. GDP is about location (where the production happens); GNP is about ownership (who owns the factors that produce it)
Students frequently assume that a rising GDP means everyone is better off. GDP says nothing about how income is distributed across the population
Students sometimes think the sale of a used car or an existing house adds to GDP. It does not, because GDP measures only new production
⚠️ Be able to name and describe all three approaches to measuring GDP and explain why they should give the same result
⚠️ Know the expenditure identity Y = C + I + G + NX and what each component represents
⚠️ Understand the GDP vs GNP distinction and the role of net factor payments: GDP + NFP = GNP
⚠️ Be ready to explain why GDP includes only final goods (to avoid double-counting) and why used goods are excluded
⚠️ Know the main categories of income in the income approach: compensation of employees, gross operating surplus, gross mixed income, taxes less subsidies on production, taxes less subsidies on products and imports
⚠️ Understand what home production and the underground economy are, why they are excluded, and their approximate size relative to GDP
True or false: GDP and GNP always give the same number for a given country.
False. They differ by net factor payments from abroad (NFP).
Fill in the blank: GDP counts only ________ goods to avoid double-counting.
Final.
True or false: If you sell your used car, that transaction is counted in GDP.
False. Used goods are not new production.
Fill in the blank: The expenditure identity is Y = __ + __ + __ + __.
C + I + G + NX.
True or false: Government services are valued at their market price in national income accounts.
False. They are valued at their cost of production (mainly employee wages), because there is no market price for most government services.
Q: Name the three approaches to measuring GDP and briefly describe each.
A: (1) Product approach: sums the value added at each stage of production. (2) Income approach: sums all incomes earned in production (wages, profits, rents, interest, net taxes). (3) Expenditure approach: sums all spending on final goods and services (Y = C + I + G + NX). All three should yield the same GDP figure.
Q: Explain the difference between GDP and GNP. Give an example involving Canada.
A: GDP measures the market value of final goods and services produced within a country's borders, regardless of ownership. GNP measures the market value produced by a country's own factors of production, wherever they are. A Toyota plant in Ontario contributes to Canadian GDP but to Japanese GNP. A Scotiabank branch in Mexico City contributes to Mexican GDP but to Canadian GNP. The formula is GDP + NFP = GNP.
Q: Why does GDP include only final goods? What problem would arise if intermediate goods were also counted?
A: Including intermediate goods would cause double-counting. The flour used to make bread would be counted once as flour and again as part of the bread's price. Counting only final goods, or equivalently summing value added at each stage, ensures each unit of production is counted exactly once.
Q: What is home production, and why is it excluded from GDP?
A: Home production includes unpaid activities like housework, childcare, and volunteer work that would have a market price if outsourced. It is excluded because there are no reliable market transactions to measure. In Canada, home production is estimated at roughly 20% of the economy's value.
Q: How are government services valued in the national accounts, and what limitation does this create?
A: Government services are valued at their cost of production, primarily the wages paid to government employees. This is a practical workaround because most government services (defence, policing, public education) are not sold at market prices. The limitation is that improvements in the quality of government services are not captured, so GDP may understate public-sector contributions.
The expenditure identity Y = C + I + G + NX is the backbone of everything that follows in macroeconomics. When the course covers the IS-LM model, each of these components will be modelled as a function of interest rates and income. The distinction between nominal and real GDP (not yet covered) builds on this measurement framework and is essential for understanding inflation. The GDP vs GNP distinction also becomes important when studying open-economy macroeconomics and the balance of payments.
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