What it means
Every sale in an economy is also someone's income, so production, spending and income should all add up to the same total. National income accounting records this circular flow using three equivalent approaches: the production approach, the expenditure approach and the income approach.
In practice statisticians use all three and reconcile the differences. The most quoted measure is GDP, the total value of final goods and services produced inside a country in a year.
Gross national income, or GNI, adjusts GDP to include income earned abroad by the country's residents and subtract income paid to foreigners. Net national income then subtracts depreciation, the wearing out of capital such as machinery.
The expenditure approach splits GDP into consumption by households, investment by businesses, spending by government and net exports, which are exports minus imports. This breakdown shows what is driving growth, such as a consumer boom or a rise in business investment.
Businesses use these figures to size markets, set sales targets and judge the economic cycle. A company planning to enter a new country will look at GDP per person, growth and the shares of consumption and investment.
Lenders and investors use them to assess country risk. Be careful with their limits.
National income figures miss unpaid work, informal activity and environmental damage, and they are often revised as better data arrives. They measure the size of activity, not the wellbeing or fairness of its distribution.
There is also a distinction between nominal and real figures. Nominal GDP is measured at current prices, so it rises with inflation, while real GDP removes the effect of price changes to show the actual growth in output.
When you compare growth across years, use the real figure.
In practice
Real-world examples.
Example
A retail chain deciding where to open next studies national income data for three countries. It picks the one where household consumption is growing fastest and forms a larger share of GDP. The team double-checks the choice against population and income data.
Example
A government economist notices that investment fell as a share of GDP while consumption rose. She warns that growth may be less durable because it relies on spending instead of building capacity. Her briefing recommends policies that encourage business investment.
Example
A bank's country risk analyst compares GDP with GNI for a small economy where many residents work overseas and send money home. She finds that GNI is notably higher than GDP, which supports the country's ability to repay its debts. She treats the remittance flows as a stable source of foreign currency.
Formula
Calculation
GDP = Consumption + Investment + Government spending + (Exports - Imports)
GNI = GDP + Net income from abroad
Net national income = GNI - Depreciation
Suppose an economy has consumption of $700 billion, investment of $200 billion, government spending of $250 billion, exports of $150 billion and imports of $100 billion. GDP is $700 billion + $200 billion + $250 billion + ($150 billion - $100 billion) = $1,200 billion.
If residents earn $20 billion more from abroad than foreigners earn at home, GNI is $1,200 billion + $20 billion = $1,220 billion. With depreciation of $150 billion, net national income is $1,220 billion - $150 billion = $1,070 billion.Case study
Seen in the real world.
Zenmark is an illustrative, fictional country whose statistics office reported GDP growth of 4% in a year. A manufacturer planning a factory there was pleased until its analyst broke the figure into components.
Most of the growth came from government spending and imports of consumer goods, while business investment was flat. The analyst concluded that demand for industrial products was weaker than the headline suggested and reduced the planned factory size by a third.
In this illustrative story, the following year investment did fall and growth slowed to 1.5%. The example shows why the composition of national income matters as much as the headline number. The manufacturer now reviews the components every quarter before approving investment.
Watch out
Common mistakes.
- Assuming GDP and GNI are the same, when GNI adds income earned abroad and subtracts income paid to foreigners.
- Treating GDP as a measure of wellbeing, when it ignores distribution, unpaid work and environmental costs.
- Ignoring revisions, when initial estimates are often updated as more data comes in, sometimes by a full percentage point.
Questions
People also ask.
What does national income accounting measure?
It measures a country's production, income and spending over a period, usually a quarter or a year.
What are the three approaches?
Production, expenditure and income, which should give the same total in theory. In practice small statistical discrepancies remain and are reported.
Why do businesses care?
The figures reveal market size, growth and the balance of demand, which affect sales, investment and credit decisions.
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