Economic and Business Environment · National Income Accounting and Related Concepts

Basic Concepts of National Income: GDP, GNP, NNP Explained

Updated 11 October 2026 · Fact-checked

National income measures the value of goods and services a country produces in a year. GDP counts production inside the territory; GNP adds net factor income from abroad. Deduct depreciation to get net figures. Adjust for taxes and subsidies to move between market price and factor cost. Real GDP removes price changes.

Understand Basic Concepts of National Income

National income is the money value of all final goods and services produced by an economy in a year. Only final goods count. Intermediate goods are left out because their value is already inside the final price. Counting them would be double counting.

GDP (Gross Domestic Product) is the value of final goods and services produced within the domestic territory of a country, by anyone, residents or foreigners. GNP (Gross National Product) is the value produced by the normal residents of a country, wherever they work. So GNP = GDP + net factor income from abroad (NFIA). NFIA is income earned by residents abroad minus income earned by foreigners in India. If a foreign company's Indian plant sends profit home, it is in India's GDP but not India's GNP.

Gross means before deducting depreciation. Net means after deducting depreciation (consumption of fixed capital). So NDP = GDP − depreciation and NNP = GNP − depreciation.

Valuation can be at market price (what buyers actually pay, including indirect taxes and net of subsidies) or at factor cost (what factors of production receive: rent, wages, interest, profit). The bridge is net indirect taxes, which are indirect taxes minus subsidies. So market price = factor cost + net indirect taxes. NNP at factor cost is called national income.

Nominal GDP uses current-year prices, so it can rise just because prices rose. Real GDP uses base-year prices and shows only the change in output. The GDP deflator compares the two and acts as a price index for all goods and services produced.

Key rules to remember

GNP from GDP: GNP = GDP + Net Factor Income from Abroad (NFIA); NFIA = factor income received from abroad − factor income paid abroad. It can be negative.
Net from gross: NDP = GDP − Depreciation; NNP = GNP − Depreciation; Depreciation is also called consumption of fixed capital.
Market price and factor cost: Market price = Factor cost + Net indirect taxes; Net indirect taxes = indirect taxes − subsidies. So factor cost = market price − net indirect taxes.
National income: National income = NNP at factor cost = NNP at market price − Net indirect taxes; Also written NNP at FC.
Full chain: NNP at FC = GDP at MP + NFIA − Depreciation − Net indirect taxes; Use this when the question gives many items.
Real GDP: Real GDP = Σ (base-year price × current-year quantity); Price is fixed at the base year, so only quantity changes the value.
GDP deflator: GDP deflator = (Nominal GDP ÷ Real GDP) × 100; Base-year value is 100. Real GDP = (Nominal GDP ÷ Deflator) × 100.

How to solve Basic Concepts of National Income questions

Most questions are either a definition or difference answer, or a numerical that converts one measure into another. This method handles both.

1Read what is asked: which measure (GDP, GNP, NDP, NNP) and at which valuation (market price or factor cost).
2List the given items and label each: NFIA, depreciation, indirect taxes, subsidies, nominal or real values.
3Decide the direction. Domestic to national: add NFIA. Gross to net: subtract depreciation. Market price to factor cost: subtract net indirect taxes.
4Calculate net indirect taxes first (indirect taxes − subsidies) if only the two are given.
5Apply the conversions in order and write each line with its label.
6For nominal and real problems, use the deflator formula and check that the base-year deflator equals 100.
7Check the sign and size. NNP at FC should be smaller than GDP at MP when NFIA is small, because you subtract depreciation and net indirect taxes.
8State the answer with units, such as ₹ crore.

Quickest way: Ladder method for conversions

When to use it: Use it for numericals that give several items and ask for one measure.

Write the ladder: GDP at MP → (+NFIA) GNP at MP → (−Depreciation) NNP at MP → (−Net indirect taxes) NNP at FC.
Mark the starting rung and the target rung.
Move up or down. Going down the ladder, subtract. Going the other way, reverse the sign.
Ignore items not on your path, such as extra figures given as distractors.
For a deflator question, find Nominal ÷ Real × 100 and confirm the answer is above 100 if prices rose.

Common mistakes in Basic Concepts of National Income

Saying GDP includes only income of Indian citizens.
The word domestic is confused with national.
Fix: GDP is about location: produced within the territory. GNP is about residents. Remember GNP = GDP + NFIA.
Adding subsidies and subtracting only indirect taxes, or the reverse, when moving to factor cost.
The direction of the adjustment is memorised without reasoning.
Fix: Buyers pay taxes on top and subsidies lower the price. So factor cost = market price − indirect taxes + subsidies, which is market price − net indirect taxes.
Subtracting depreciation to get GDP or GNP.
Gross and net are mixed up.
Fix: Gross includes depreciation. Only net measures deduct it. GDP is the larger figure than NDP.
Treating a rise in nominal GDP as growth in output.
Price effect is ignored.
Fix: Compare real GDP across years. Nominal GDP can rise with prices alone.
Inverting the deflator formula and writing Real ÷ Nominal × 100.
Students forget which one carries the price change.
Fix: Nominal is on top. Nominal uses current prices, so nominal ÷ real shows the price level relative to the base year.
Counting intermediate goods such as steel sold to a car maker.
Every sale seems like production.
Fix: Count only final goods, or sum value added at each stage.

Worked examples

Example 1

From the following (₹ crore), find GNP at market price, NNP at market price and national income: GDP at market price 5,000; net factor income from abroad (−)100; depreciation 400; indirect taxes 650; subsidies 150.

Show the solution

GNP at MP = GDP at MP + NFIA = 5,000 + (−100) = 4,900.
NNP at MP = GNP at MP − Depreciation = 4,900 − 400 = 4,500.
Net indirect taxes = 650 − 150 = 500.
National income = NNP at FC = 4,500 − 500 = 4,000.

Answer: GNP at MP = ₹4,900 crore; NNP at MP = ₹4,500 crore; National income = ₹4,000 crore.

Example 2

An economy produces only rice. In the base year it produced 100 tonnes at ₹20,000 per tonne. In the current year it produced 120 tonnes at ₹25,000 per tonne. Find nominal GDP, real GDP, the GDP deflator and the growth in real GDP.

Show the solution

Nominal GDP = 120 × ₹25,000 = ₹30,00,000.
Real GDP = 120 × ₹20,000 (base-year price) = ₹24,00,000.
GDP deflator = (30,00,000 ÷ 24,00,000) × 100 = 125.
Base-year GDP = 100 × ₹20,000 = ₹20,00,000, so real GDP growth = (24,00,000 − 20,00,000) ÷ 20,00,000 × 100 = 20%.

Answer: Nominal GDP ₹30,00,000; real GDP ₹24,00,000; deflator 125; real GDP growth 20%. Prices rose 25% and output rose 20%.

Exam tips

For the difference between GDP and GNP, write four points: basis (territory or residents), formula, treatment of NFIA, and an example.
In numericals, write the formula line first. Marks are often given for the method even if arithmetic slips.
Show net indirect taxes as a separate line before converting to factor cost.
Define nominal and real GDP with a small numeric example. It earns more than definitions alone.
Label every figure with its measure and valuation, such as NNP at FC, so the examiner can follow.

Practice questions from National Income Accounting and Related Concepts

Basic Concepts of National Income in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

CA FoundationNational Income Aggregates (GDP, GNP, NNP)

Basic Concepts of National Income: frequently asked questions

What is the difference between GDP and GNP?

GDP counts output produced within the country's territory, whoever produces it. GNP counts output produced by the country's residents, wherever they are. GNP = GDP + net factor income from abroad.

What is the formula for GDP at market price and factor cost?

Market price = factor cost + net indirect taxes, where net indirect taxes are indirect taxes minus subsidies. So GDP at factor cost = GDP at market price − net indirect taxes.

What is the difference between nominal and real GDP?

Nominal GDP is valued at current-year prices. Real GDP is valued at base-year prices. Real GDP shows true change in output because the effect of price change is removed.

What is the GDP deflator and how is it calculated?

The GDP deflator is a price index that covers all domestically produced goods and services. It equals nominal GDP divided by real GDP, multiplied by 100. A value above 100 means prices are higher than in the base year.