How to use a country in a case
The three numbers to pull for any market entry or sizing question (people, spending power and real growth), where each comes from, and the traps that make a country estimate wrong.
Firm processes and online tests change from year to year and differ by office. Use this to prepare, and confirm the exact current steps on the firm's own careers page.
Key takeaways
- For any country in a sizing or market entry case, pull three numbers: how many people are in the target group, what they can spend, and how fast the market grows in real terms.
- Number one, people in the target group: total population times the share that fits (by age, city or income).
- Number two, spending power: what one buyer spends on this kind of product in a year.
Key idea
For any country in a sizing or market entry case, pull three numbers: how many people are in the target group, what they can spend, and how fast the market grows in real terms. Say where each comes from and which year it is for.
The method
- 1Pin the buyer. Who exactly buys this product: all adults, city households, children aged 5 to 14, small firms?
- 2Number one, people in the target group: total population times the share that fits (by age, city or income). Population comes from the IMF World Economic Outlook database or the national statistics office; age and city shares from the World Bank or a census.
- 3Number two, spending power: what one buyer spends on this kind of product in a year. Anchor it on GDP per person or, better, on household income or spending from the national household survey, then on a price you can check in shops.
- 4Number three, real growth: the IMF's real GDP growth projection for the coming years is the base for volume growth; add expected inflation if you need growth in local money.
- 5Multiply, sanity-check against something you know (a big company's sales in that country, or the same market in a similar country), and say so what.
| Number | What it tells you | Where to look first | Watch out for |
|---|---|---|---|
| People in the target group | How many possible buyers there are | IMF World Economic Outlook database (population); World Bank World Development Indicators (age, urban share); national census | Different years and definitions across sources |
| Spending power | What one buyer can spend | IMF (GDP per person); national household income or spending surveys; shop prices | Average versus median; US dollars versus local money; purchasing power |
| Real growth | How fast volumes grow | IMF World Economic Outlook and its updates; central bank reports; statistics office releases | Projections versus actual figures; fiscal years (India runs April to March) |
So-what
Three numbers, each with a source and a year, are enough to frame almost any country question.
Worked case
Sizing a market entry: toothpaste in urban Indonesia
The prompt
A fictional European oral care brand is thinking of entering Indonesia, starting in cities. Using the data shown (IMF and World Bank figures, plus one illustrative assumption of USD 3 spent on toothpaste per urban person per year), size the urban toothpaste market today and next year.
The structure
- Market = urban people x spend per person, grown by real growth and inflation
- People: population x urban share
- Spend: USD 3 per urban person a year (an assumption to test)
- Key: Growth: real growth and inflation together
The exhibit
| Input | Value | Year |
|---|---|---|
| Population, millions (IMF) | 284.4 | 2,025 |
| Urban share, percent (World Bank) | 59.4 | 2,025 |
| Real GDP growth, percent (IMF projection) | 5 | 2,026 |
| Inflation, percent (IMF projection) | 3 | 2,026 |
| Spending per urban person, USD a year (illustrative assumption) | 3 | 2,026 |
Sources: IMF World Economic Outlook database (April 2026); World Bank World Development Indicators; checked 2026-10-01. The spending figure is an assumption for practice, not data.
Working it through
1. Urban people
Population times the urban share.
Urban population (millions):284.4 × 0.594 = 1692. Market today
Urban people times USD 3 each a year.
Urban toothpaste market (USD millions):284.4 × 0.594 × 3 = 5073. Growth in money terms
Real growth of 5.0 percent and inflation of 3.0 percent together: 1.05 times 1.03, minus 1.
Growth in money terms (percent):(1.05 × 1.03 - 1) × 100 = 8.154. Market next year
Today's market grown by 8.15 percent. This assumes toothpaste spending grows with the economy, which is a simplification.
Urban toothpaste market next year (USD millions):284.4 × 0.594 × 3 × 1.0815 = 548
What the exhibit shows
Two sourced numbers give the buyers, one assumption gives the spend, and two IMF projections give the growth.
The recommendation
Urban Indonesia has about 169 million people. At an assumed USD 3 each a year, urban toothpaste is worth about USD 507 million today and about USD 548 million next year, if the rupiah holds its value against the dollar. That is large enough to be worth a closer look, but the decision turns on two things this sizing does not answer: the real spending per person (check shelf prices and how often people buy) and how much share a new brand could win from established players. Next steps: test the USD 3 assumption in shops, and work out the share needed to pay back the cost of entry.
Risks: The spending figure is an assumption; a change of 1 dollar moves the market by about USD 169 million.; Spending on toothpaste may not grow with the economy; it depends on brushing habits and premium products.; A weaker rupiah would shrink the market measured in US dollars even if volumes grow..
Five traps when you use a country
- Mixing years and sources in one calculation without saying so. Name both.
- Using nominal growth from a high-inflation country as if it were volume growth.
- Forgetting fiscal years. The IMF shows India's figures on its April to March fiscal year, so "2025" means April 2025 to March 2026.
- Treating a projection as a fact. IMF numbers for the current year are estimates, and they change with each update.
- Using one national average for a country with big regional gaps, such as cities and villages in India or China.
A client wants to sell school bags in Nigeria. Which number should you pull first to find the people in the target group?
Which source would you use first for every country's population and real growth projection, so that a comparison across countries stays on the same basis?
Sales of a product in India rise 9 percent in a year when inflation is 4 percent. Roughly what is the real growth?
Sources for this lesson (7)
- Recognized public explanations of case-interview concepts and terms
- IMF World Economic Outlook database, April 2026: population, millions (IMF DataMapper, indicator LP)
- IMF World Economic Outlook database, April 2026: real GDP growth, annual percent change (IMF DataMapper, indicator NGDP_RPCH)
- IMF World Economic Outlook database, April 2026: inflation, average consumer prices, annual percent change (IMF DataMapper, indicator PCPIPCH)
- IMF World Economic Outlook database, April 2026: GDP per capita at current prices, USD (IMF DataMapper, indicator NGDPDPC)
- World Bank, World Development Indicators: urban population, percent of total (2025 values)
- World Bank, World Development Indicators: population aged 0 to 14, percent of total (2025 values)
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