Skip to content

Business Economics · Determination of National Income

National Income Aggregates (GDP, GNP, NNP) for CA Foundation

Updated 1 October 2026 · Fact-checked

National income aggregates measure an economy's output and income. GDP counts output within the country's borders. GNP adds net factor income from abroad. NNP subtracts depreciation. Market price includes indirect taxes less subsidies; factor cost excludes them. To solve numericals, start from GDP at market price and adjust step by step.

Understand National Income Aggregates (GDP, GNP, NNP)

Every country produces goods and services. National income aggregates are different ways of measuring that total production, or the income it creates. Each aggregate answers a slightly different question.

GDP (Gross Domestic Product) is the market value of all final goods and services produced within the domestic territory in a year. It does not matter who owns the factory. A foreign company's output in India counts in India's GDP. GNP (Gross National Product) counts what the country's own residents produce, wherever they produce it. So GNP = GDP + Net Factor Income from Abroad (NFIA). NFIA is income earned by residents abroad minus income earned by non-residents in the country.

Gross means before deducting depreciation (consumption of fixed capital). Net means after deducting it. So NDP = GDP − depreciation, and NNP = GNP − depreciation. Depreciation is the wear and tear of capital during the year.

Next comes the price basis. Market price (MP) is what buyers pay, so it includes indirect taxes (like GST) and excludes subsidies. Factor cost (FC) is what factors of production actually receive: rent, wages, interest and profit. To move from market price to factor cost, subtract net indirect taxes (indirect taxes − subsidies). So FC = MP − NIT.

NNP at factor cost is called National Income. Two more terms follow. Personal income is the income actually received by households from all sources, including transfer payments. Disposable income is personal income minus personal direct taxes. Households can spend or save it.

Key formulas to remember

GNP at market price
GNP(MP) = GDP(MP) + NFIA
NFIA = income earned from abroad − income paid to foreigners. It can be negative.
Net aggregates
NDP(MP) = GDP(MP) − Depreciation; NNP(MP) = GNP(MP) − Depreciation
Depreciation is also called consumption of fixed capital.
Market price to factor cost
FC = MP − Net Indirect Taxes
Net indirect taxes = indirect taxes − subsidies. Apply this to any aggregate.
National Income
National Income = NNP(FC) = NNP(MP) − NIT
Equivalent: GNP(MP) − Depreciation − NIT.
Domestic vs national
NNP(FC) = NDP(FC) + NFIA
Add NFIA to move from domestic to national.
Personal income
Personal Income = National Income − Undistributed profits − Corporate tax − Social security contributions + Transfer payments
Transfer payments include pensions and unemployment allowances.
Disposable income
Disposable Income = Personal Income − Personal direct taxes
Disposable income = Consumption + Saving.

How to solve National Income Aggregates (GDP, GNP, NNP) questions

Use one fixed chain so you never mix up the adjustments. Move one step at a time from the given figure to the asked figure.

  1. 1Write down every item given and mark each as GDP, GNP, NFIA, depreciation, indirect taxes, subsidies, or direct taxes.
  2. 2Note the target: is it GDP, GNP, NDP or NNP, and at market price or factor cost?
  3. 3Decide the domestic-to-national step: add NFIA to go from domestic to national. Subtract it to go back.
  4. 4Decide the gross-to-net step: subtract depreciation to go from gross to net.
  5. 5Decide the price step: subtract net indirect taxes (indirect taxes − subsidies) to go from MP to FC. Add them to go from FC to MP.
  6. 6Calculate in one line, keeping signs carefully. Treat a negative NFIA as a subtraction.
  7. 7Match your result with the options and check the unit and the price basis.

Quickest way: The three-switch method

When to use it: Use it for every numerical MCQ. It takes under a minute and avoids formula recall errors.

  1. Think of three switches: Domestic/National (NFIA), Gross/Net (depreciation), MP/FC (net indirect taxes).
  2. Compare the starting aggregate and the target aggregate. Flip only the switches that differ.
  3. Apply the direction: Net reduces the figure by depreciation. FC reduces it by net indirect taxes (if positive). National adds NFIA, which may be positive or negative.
  4. Eliminate options. If the target is Net or FC, the answer should be smaller than the gross or MP figure (unless subsidies exceed taxes or NFIA is large and positive).
  5. If an item is not needed (for example, direct taxes when asked for NNP), ignore it. Do not skip a question over extra data.

Common mistakes in National Income Aggregates (GDP, GNP, NNP)

  • Subtracting NFIA when going from GDP to GNP, or adding it when NFIA is negative.

    Students memorise 'add NFIA' without checking its sign or what it means.

    Fix: Remember GNP = GDP + NFIA. If the question gives a negative NFIA, the result falls. If it gives income paid abroad and income earned abroad separately, compute earned − paid first.

  • Adding subsidies and subtracting only taxes, or the reverse, when converting MP to FC.

    Students forget that subsidies lower market prices.

    Fix: Use FC = MP − (indirect taxes − subsidies). Taxes raise MP above FC. Subsidies pull MP below FC.

  • Treating GDP at factor cost and National Income as the same thing.

    Both use factor cost, so the labels get blurred.

    Fix: National Income is NNP at factor cost. It is both national and net. GDP(FC) is domestic and gross.

  • Forgetting depreciation when asked for a 'net' aggregate.

    Students focus on NFIA and taxes and miss the word 'net'.

    Fix: Underline Gross or Net in the question first. Net always means subtract depreciation.

  • Confusing personal income with disposable income, and using direct taxes in the wrong place.

    Both are household income measures with similar names.

    Fix: Personal income is before personal direct taxes. Disposable income is after them. Indirect taxes only matter for the MP/FC step.

  • Treating transfer payments as part of national income.

    They are income to households, so they look productive.

    Fix: Transfers like pensions are not payment for current production, so they are not in national income. They are added only when moving to personal income.

Worked examples

Example 1

GDP at market price is ₹5,00,000 crore. Net factor income from abroad is ₹10,000 crore and depreciation is ₹40,000 crore. What is NNP at market price? (a) ₹4,50,000 crore (b) ₹4,70,000 crore (c) ₹5,30,000 crore (d) ₹5,50,000 crore

Show the solution
  1. Target: NNP(MP). Switches needed: domestic to national (add NFIA) and gross to net (subtract depreciation).
  2. GNP(MP) = 5,00,000 + 10,000 = 5,10,000.
  3. NNP(MP) = 5,10,000 − 40,000 = 4,70,000.
  4. Price basis stays MP, so no tax adjustment.

Answer: (b) ₹4,70,000 crore

Example 2

GNP at market price is ₹8,00,000 crore. Depreciation is ₹60,000 crore, indirect taxes are ₹90,000 crore and subsidies are ₹20,000 crore. What is National Income? (a) ₹6,70,000 crore (b) ₹7,10,000 crore (c) ₹7,30,000 crore (d) ₹7,50,000 crore

Show the solution
  1. National Income is NNP at factor cost.
  2. NNP(MP) = 8,00,000 − 60,000 = 7,40,000.
  3. Net indirect taxes = 90,000 − 20,000 = 70,000.
  4. NNP(FC) = 7,40,000 − 70,000 = 6,70,000.

Answer: (a) ₹6,70,000 crore

Example 3

National income is ₹6,00,000 crore. Undistributed profits are ₹20,000 crore, corporate tax is ₹30,000 crore, social security contributions are ₹10,000 crore and transfer payments are ₹50,000 crore. Personal direct taxes are ₹40,000 crore. What is disposable income? (a) ₹5,50,000 crore (b) ₹5,40,000 crore (c) ₹5,90,000 crore (d) ₹6,40,000 crore

Show the solution
  1. Personal income = 6,00,000 − 20,000 − 30,000 − 10,000 + 50,000.
  2. Deductions total 60,000, so 6,00,000 − 60,000 = 5,40,000. Adding transfers: 5,40,000 + 50,000 = 5,90,000.
  3. Disposable income = personal income − personal direct taxes = 5,90,000 − 40,000 = 5,50,000.

Answer: (a) ₹5,50,000 crore

Exam tips

  • Read the target aggregate in the last line first. Then pick only the switches you need.
  • Watch the words 'domestic', 'national', 'gross', 'net', 'market price' and 'factor cost'. Examiners change one word to create a trap option.
  • Expect distractor data such as direct taxes in an NNP question. Ignore anything the chain does not need.
  • Learn the definitions too. Conceptual MCQs ask which aggregate includes foreign firms' output or which one equals National Income.
  • With 0.25 negative marking, attempt a numerical only if your chain is clear. Skip if the data is confusing and return later.

Practice questions from Determination of National Income

National Income Aggregates (GDP, GNP, NNP): frequently asked questions

What is the difference between GDP and GNP?

GDP measures output produced within the country's borders, whoever owns the factors. GNP measures output by the country's residents, wherever they work. The gap is net factor income from abroad: GNP = GDP + NFIA.

What is the GNP at factor cost formula?

GNP(FC) = GNP(MP) − net indirect taxes, where net indirect taxes = indirect taxes − subsidies. You can also write it as GDP(FC) + NFIA.

How do you calculate NNP at factor cost?

Start with GNP at market price. Subtract depreciation to get NNP at market price. Then subtract net indirect taxes to get NNP at factor cost, which is National Income.

What is the difference between personal income and disposable income?

Personal income is the total income households actually receive, including transfer payments. Disposable income is what remains after paying personal direct taxes. Households use it for consumption and saving.