Economic growth: the rate of change of real GDP, and GNI
This unit opens Unit 2, Macroeconomic performance and policy, which is examined on the WEC12 paper.
It is the measuring kit for the whole of macroeconomics: before anyone can say whether an economy is doing well, they need numbers for output, prices, jobs and trade.
In the June 2024, January 2025 and June 2025 papers this topic earned more of the compulsory marks than any other Unit 2 topic, through multiple-choice items, Section B calculations and short answers, Define parts and a Discuss [14] on GDP.
This first section teaches how economists measure growth, and why they sometimes prefer GNI to GDP.
The idea: is the economy getting bigger, and are people better off?
Every news bulletin reports "growth".
Behind the word is one question: is the country producing more goods and services than it did a year ago?
If it is, there is more to go round: more food, housing, healthcare and leisure, more jobs, and more tax revenue for schools and hospitals.
If output shrinks, firms cut jobs, incomes fall and governments face hard choices.
Measuring output accurately is the first step in judging every government policy in this unit.
The first thing to know, word for word:
- Real GDP growth: The rate of change of real Gross Domestic Product (GDP) as a measure of economic growth and living standards.
- An alternative measure of national income: Gross National Income (GNI) as an alternative measure of national income.
- Gross Domestic Product (GDP): the total value of goods and services produced within a country's borders in a given period, usually a year.
- Economic growth: an increase in real GDP (real output) over time, measured as the percentage change in real GDP.
- Real output: output adjusted for inflation.
- GNI: GDP plus net income from abroad (which may be positive or negative).
The last two lines are the wordings the WEC12 schemes credit.
Learn them word for word: each has two halves, and a Define [2] or the knowledge marks of an Explain [4] are given one mark per half.
(WEC12, 1 hour 45 minutes, 80 marks)
- Section A: six multiple-choice questions, 1 mark each for the key only. Section B: five 4-mark items in a fixed order: Q7 Explain one, Q8 Draw, Q9 Calculate, Q10 and Q11 Explain. Section C: one data response with (a) Define [2] first and (e) Discuss [14] last, and an Explain [4], an Analyse [6] and an Examine [8] between them in any order. Section D: one Evaluate [20] essay from two. Allow about 1.3 minutes per mark.
- Splits: Explain one = Knowledge 1, Analysis 2, Application 1; Explain the term or the difference = Knowledge 2, Application 2; Draw = Knowledge 1, Application 3; Calculate = Knowledge 1 (the formula), Application 3; Define = Knowledge 2; Analyse = Knowledge 2, Application 2, Analysis 2; Examine = Knowledge 2, Application 2, Analysis 2, Evaluation 2, the evaluation given "1+1 or 2+0".
- Each (1) in a scheme is one mark; a "/" separates wordings that earn the same mark.
- Calculate: a correct answer alone earns all 4 marks only with its unit ($ billion, %, percentage points). A missing or wrong unit, or a wrong sign, earns 3. A multiplier has no unit.
- Discuss [14]: KAA out of 8 (levels 1-3, 4-6, 7-8) and evaluation out of 6 (levels 1-2, 3-4, 5-6); no conclusion is needed. Evaluate [20]: KAA out of 12 (1-3, 4-6, 7-9, 10-12) and evaluation out of 8 (1-3, 4-6, 7-8); the top evaluation level needs an informed judgement.
- Every essay ends "Refer to a country of your choice in your answer": with no country used inside the analysis, KAA stops at Level 3 (9 of 12).
- Examiners take your best two points in each strand, so two developed chains in context beat a long list.
Why the rate of change of real GDP?
GDP adds up the value of everything produced inside a country.
To turn it into a measure of growth, you need two things.
First, real, not nominal. Nominal GDP is measured at the prices of the year it is produced in.
If a country makes exactly the same goods this year as last year but prices rise by 5%, nominal GDP rises by 5% while output has not changed at all.
Real GDP removes the effect of price changes, so it moves only when the volume of output moves.
That is why the credited wording of real output is "output adjusted for inflation".
The next section shows how the adjustment is made.
Second, the rate of change. A level of real GDP on its own says little: $400 billion is large for a small economy and tiny for a large one.
Growth is the percentage change from one period to the next:
(no formula sheet in WEC12)
- In words: the change in real GDP divided by the original real GDP, multiplied by 100.
- In symbols: growth rate (%) = (real GDP this year − real GDP last year) ÷ real GDP last year × 100.
- Unit of the answer: %.
Why it is a measure of living standards too
The wording you learn links real GDP to living standards as well as growth.
The chain is: more real output means more goods and services available; more output needs more workers, so incomes rise; higher incomes let households buy more; higher output also raises tax revenue, so governments can provide more health care and education.
So a rising real GDP usually goes with rising living standards.
The section on the limitations of GDP (later in this unit) explains why the link is not exact: population growth, the distribution of income, the hidden economy, the environment and leisure all matter.
For now, note the word real again: a household is better off only if its income buys more, not if prices and incomes both rise.
GNI: whose income is it?
GDP measures output produced inside the country, whoever owns the firms.
But some of the income from that output leaves the country.
A foreign-owned car factory sends its profits to its parent company abroad; foreign investors receive interest on bonds.
In the other direction, residents earn income from abroad: profits from factories they own overseas, interest and dividends on foreign assets, and wages earned by residents working abroad for short periods.
Statisticians call these flows primary income.
Gross National Income adjusts GDP for these flows:
- In words: GNI is GDP plus net income from abroad.
- In symbols: GNI = GDP + (income received from abroad − income paid abroad).
- Unit of the answer: the currency ($ billion).
So GNI measures the income that belongs to the country's residents, wherever it was produced.
For most countries GNI and GDP are close.
They differ a lot where foreign ownership is large or where residents own many assets abroad.
A real case: Ireland
Ireland is the best-known example of GDP overstating national income.
Many multinational firms, especially in pharmaceuticals and technology, have their European base in Ireland.
Their output counts in Irish GDP, but much of the profit is paid out to owners abroad.
World Bank data for 2024 put Ireland's GDP at about US$609 billion and its GNI at about US$458 billion, so GNI was only about 75% of GDP.
In 2015, when several firms moved valuable intellectual property to Ireland, Irish GDP was first reported to have grown by more than 25% in a single year, although very little changed in the lives of Irish households.
The chart below shows the gap for 2022 to 2024.
For Ireland, GNI is a better guide to the income available to residents, which is why Ireland's own statistics office also publishes an adjusted measure of national income.
The opposite case is a country whose residents earn a lot abroad: GNI is then above GDP.
Where many workers send money home from abroad (remittances), those transfers are secondary income, not primary income, so they appear in the current account but not in GNI.
Connecting it
Real GDP growth is the first macroeconomic objective and the headline result of every AD/AS diagram, where it appears as a rise in real output on the horizontal axis.
GNI links to the balance of payments: the primary income that separates GNI from GDP is one of the four parts of the current account.
The table shows real GDP for Vellmark.
Year
Real GDP ($ billion)
2024
318.0
2025
327.5
Calculate the rate of economic growth in Vellmark in 2025.
Show your workings.
1. Growth rate = (real GDP 2025 − real GDP 2024) ÷ real GDP 2024 × 100 (1) Knowledge
2. 327.5 − 318.0 = 9.5 ($ billion) (1) Application
3. 9.5 ÷ 318.0 × 100 (1) Application
4. = 2.99% (1) Application
Answer: 2.99%.
Written as "2.99" with no % sign it earns 3 of 4.
Meaning: Vellmark produced almost 3% more goods and services than in 2024, a steady rate for a developed economy.
Real GDP in Pellora fell from $54.2 billion in 2024 to $53.1 billion in 2025.
Calculate the rate of economic growth in 2025.
1. Growth rate = (53.1 − 54.2) ÷ 54.2 × 100
2. = −1.1 ÷ 54.2 × 100
3. = −2.03%
Answer: −2.03%.
The minus sign is part of the answer: "2.03%" would describe growth, not a fall, and a wrong sign costs a mark.
Output fell by about 2%, so firms needed fewer workers and incomes fell on average.
In 2025 Dunmore's GDP was $412.0 billion. Its residents received $18.5 billion of primary income from abroad, and $46.0 billion was paid to foreign owners of firms and assets in Dunmore.
Calculate Dunmore's GNI.
1. GNI = GDP + net income from abroad (1) Knowledge
2. Net income from abroad = 18.5 − 46.0 = −$27.5 billion (1) Application
3. GNI = 412.0 + (−27.5) (1) Application
4. = $384.5 billion (1) Application
Answer: $384.5 billion. GNI is about 93% of GDP: about $1 in every $15 produced in Dunmore is income for foreign owners, so GDP overstates the income Dunmore's residents can spend.
In 2025 Kestria's GDP was $96 billion and its GNI was $104 billion, after residents received $11 billion of profits and interest from assets abroad. With reference to the data, explain what is meant by gross national income.
- GNI is GDP (1)
- plus net income from abroad (1)
- Kestria's GNI of $104 billion was $8 billion above its GDP of $96 billion (1A)
- because residents received $11 billion of profits and interest from assets abroad, more than was paid out (1A)
Answer: 4 marks: two halves of the definition and two separate data points.
Defining only GDP earned 1 mark in a recent report.
On any growth calculation, write the formula first, then each step, then the answer with "%" and its sign: the formula is the knowledge mark and the unit is needed for the fourth mark.
On a GNI item, both halves count: "GDP" and "plus net income from abroad".
- Defining GNI as "the income of a country". That is only half. The scheme wants GDP plus net income from abroad, which may be negative.
- Using nominal GDP for growth. A rise in nominal GDP can be all price rises. Growth is measured with real GDP, output adjusted for inflation.
- Dropping the sign or the unit. A fall in real GDP is negative growth; "2.03" with no % or no minus sign loses the last mark.
- Counting remittances in GNI. Money sent home by migrant workers is secondary income (a transfer). GNI adds net primary income: profits, interest, dividends and employee earnings.
Check your understanding
1. In 2024 Ireland's GNI was about 75% of its GDP. Which one of the following is the most likely explanation? (1)
- A Irish residents received more income from abroad than foreign owners took out of Ireland
- B Ireland's price level rose faster than its output
- C Profits of foreign-owned firms producing in Ireland were paid to owners abroad
- D Remittances sent home by Irish workers abroad were counted in GDP Total [1]
2. The table shows data for Larvia, $ billion.
2024
2025
Nominal GDP
200
210
Real GDP (2024 prices)
200
204
Which one of the following can be deduced from the table?
(1)
- A Larvia's rate of economic growth in 2025 was 2%
- B Larvia's rate of economic growth in 2025 was 5%
- C Larvia's output fell in 2025
- D Larvia's GNI rose by $10 billion in 2025 Total [1]
3. In 2025 Brovania's GNI was $61.4 billion. Its residents received $2.6 billion of primary income from abroad and paid $7.9 billion to foreign owners. With reference to this information, calculate Brovania's GDP in 2025. Show your workings. (4) Total [4]
4. In 2025 foreign-owned firms produced 40% of Tamsar's output and sent most of their profits abroad. With reference to this information, explain one reason why GNI may be a better measure than GDP of the income available to Tamsar's residents. (4) Total [4]
5. A student writes: "Nominal GDP rose by 6% last year, so the economy grew by 6% and everyone is 6% better off." Explain two errors in the student's statement. (4) Total [4]
6. The table shows data for Corvane.
2024
2025
Real GDP growth (%)
3.8
4.1
Net income from abroad ($ billion)
−6.2
−9.8
Foreign-owned share of manufacturing output (%)
31
38
With reference to the table, examine two reasons why Corvane's real GDP growth may overstate the rise in income available to its residents.
(8) Total [8]
Answers
1. The only correct answer is C (1). A is not correct because that would make GNI larger than GDP. B is not correct because GDP and GNI are both measured in current prices here, so inflation affects both equally. D is not correct because remittances are secondary income and are not part of GDP or GNI.
2. The only correct answer is A (1). Real GDP rose from 200 to 204: 4 ÷ 200 × 100 = 2%. B is not correct because 5% is the rise in nominal GDP, which includes price rises. C is not correct because real GDP rose, so output rose. D is not correct because the table gives no data on income from abroad, so nothing can be said about GNI.
3. GDP = GNI − net income from abroad (or GNI = GDP + net income from abroad) (1). Net income from abroad = 2.6 − 7.9 = −$5.3 billion (1). GDP = 61.4 − (−5.3) (1) = $66.7 billion (1). "66.7" without "$ billion" earns 3.
4. GDP counts all output produced in Tamsar, including the profits of foreign-owned firms (1K); but profits sent abroad are income for foreign owners, not for Tamsar's residents, so they cannot be spent by Tamsar's households (1AN); GNI subtracts this outflow, so it is lower than GDP and shows more accurately the income residents can use for consumption and saving (1AN). Foreign-owned firms produced 40% of output (1A).
5. Error 1: nominal GDP includes price rises, so real growth was less than 6% unless prices were stable; growth is measured by real GDP (1+1). Error 2: even real growth does not mean everyone is better off by the same amount: the gain is shared unequally, and population growth means GDP per person rises by less (1+1).
6. Knowledge 2, Application 2, Analysis 2, Evaluation 2. Reason 1: rising profit outflows (1K): more output is produced by foreign-owned firms, whose profits are paid abroad, so a growing share of GDP is income for foreign owners, and GNI grows more slowly than GDP (1AN); net income from abroad fell from −$6.2 billion to −$9.8 billion (1A). Reason 2: growing foreign ownership (1K): as the foreign-owned share rises, more of each extra unit of output is foreign income, so the rise in residents' income is smaller than the 4.1% growth suggests (1AN); the foreign-owned share of manufacturing rose from 31% to 38% (1A). Evaluation (1+1 or 2+0): the outflow of $3.6 billion may be small compared with total GDP, so GDP growth may still be a fair guide; foreign-owned firms still pay wages and taxes in Corvane, so much of the output does become residents' income; and in later years the investment may raise productivity and wages.