Nominal vs real GDP and measuring growth

Detail

1. Why real values matter

• The problem: GDP is measured in money (₹). Money value = quantity × price. So the ₹ figure can rise for two different reasons:
• more goods and services were produced (a rise in quantity), or

• the same goods simply became costlier (a rise in price).

• If GDP doubles, output may have doubled. Or only prices may have doubled. The ₹ figure alone cannot tell us which.

• The fix: to compare GDP across years or across countries, hold prices constant.
• MoSPI gives its own example:
• 100 bicycles are sold at ₹1,000 each, so output = ₹1,00,000.
• Next year the same 100 bicycles are sold at ₹1,100 each, so output = ₹1,10,000.
• GDP "looks" 10% higher, but real growth is 0%, because no extra bicycle was made [3].

2. Nominal GDP and real GDP: definitions

• Nominal GDP = GDP at current prices. Each year's output is valued at that same year's prices.

• It changes when quantity changes, price changes, or both change.

• Real GDP = GDP at constant prices. Every year's output is valued at the prices of one fixed base year.

• It changes only when the volume of production changes.

• Base year: the reference year whose prices (and methods) are used to compare GDP, CPI, IIP and other indicators over time [3].

• In India's official releases, "GDP at constant prices" is simply another name for real GDP [2].

3. Bread example (NCERT Class 12)

Year	Output	Price	Nominal GDP	Real GDP (2000 prices)
2000 (base)	100	₹10	₹1,000	₹1,000
2001	110	₹15	₹1,650	₹1,100

• Nominal GDP in 2001 = 110 × ₹15 = ₹1,650. This uses the price of the current year.
• Real GDP in 2001 = 110 × ₹10 = ₹1,100. This uses the price of the base year.
• Nominal growth = (1,650 − 1,000) ÷ 1,000 = 65%.
• Real growth = (1,100 − 1,000) ÷ 1,000 = 10%. This is the true rise in bread output.
• The remaining gap between 65% and 10% comes from prices.
• In the base year, nominal GDP = real GDP (₹1,000 = ₹1,000), because current prices and base prices are the same.

4. GDP deflator

• GDP deflator (a price index that shows how much the prices of all goods and services in GDP have changed since the base year):
• GDP deflator = Nominal GDP ÷ Real GDP

• As a percentage: (Nominal GDP ÷ Real GDP) × 100

• Bread example: 1,650 ÷ 1,100 = 1.5 (150%). The price of bread rose 1.5 times, from ₹10 to ₹15.

• GNP deflator: defined the same way, as nominal GNP ÷ real GNP.
• NCERT Ex. 11: nominal GNP ₹2,500 crore, real GNP ₹3,000 crore.
• Deflator = 2,500 ÷ 3,000 × 100 = 83.3%.

• It is below 100, so the price level fell compared with the base year.

• Reading the deflator:

• above 100 means prices are higher than in the base year
• equal to 100 means prices are the same

• below 100 means prices are lower than in the base year

• Going from nominal to real: Real GDP = Nominal GDP ÷ (Deflator ÷ 100).

• Example: nominal GDP ₹500 crore, deflator 125. Real GDP = 500 ÷ 1.25 = ₹400 crore.

• Deflators in practice: MoSPI uses price indices such as the CPI and WPI as deflators, applied item by item. They remove the price effect so that only the change in volume is left [3].

• India's implied GDP deflator (worked out from official levels, base 2022-23 = 100) [2]:
• 2024-25: 318.07 ÷ 299.89 × 100 ≈ 106.1
• 2025-26: 346.36 ÷ 323.12 × 100 ≈ 107.2

• So the economy-wide price level rose only about 1.1% in 2025-26.

• For how the deflator is built and how it compares with CPI and WPI, see inflation-price-indices.

5. Rule of thumb: nominal growth ≈ real growth + deflator inflation

• Exact relation: (1 + nominal growth) = (1 + real growth) × (1 + deflator inflation).
• It works as a simple sum only when the rates are small.
• India, 2025-26 (Provisional Estimates): real GDP growth 7.7%, nominal GDP growth 8.9% [2].
• Implied deflator inflation ≈ 8.9 − 7.7 = 1.2%.

• The exact figure is 1.089 ÷ 1.077 − 1 ≈ 1.1%.

• Bread example: the rule breaks down when rates are large.

• 1.65 = 1.10 × 1.50. The exact relation holds.

• Adding gives only 10% + 50% = 60%, but actual nominal growth was 65%.

• Why it matters:

• Low deflator inflation means nominal growth is close to real growth.
• So nominal GDP grows slowly.
• Tax collections and debt-to-GDP and deficit-to-GDP ratios (which are all based on nominal GDP) then look weaker, even when real growth is strong.

6. Growth measures

• Real growth rate (% change in real GDP over the previous year):
• Formula: (Real GDP this year − Real GDP last year) ÷ Real GDP last year × 100
• India, 2025-26: (323.12 − 299.89) ÷ 299.89 × 100 ≈ 7.7%

• Levels are in ₹ lakh crore at constant 2022-23 prices [2].

• Recent real GDP growth (new 2022-23 series):

• 7.2% (2023-24)
• 7.1% (2024-25, First Revised Estimate)

• 7.7% (2025-26, Provisional Estimate) [2]

• Levels, 2025-26 (PE) [2]:

• real GDP ₹323.12 lakh crore
• nominal GDP ₹346.36 lakh crore
• real GVA ₹294.91 lakh crore

• nominal GVA ₹314.87 lakh crore

• Sector-wise growth is reported as real GVA growth. GVA (Gross Value Added) = the value of output minus the value of raw materials and other inputs used to make it [3].

• Link between GDP and GVA: GDP = sum of all GVA + taxes on products − subsidies on products. The last two terms together are called net product taxes [3].
• Sector-wise real GVA growth, 2025-26 (PE) [2]:
  • Primary (agriculture, livestock, forestry and fishing, plus mining): 3.2%
  • Secondary (manufacturing, electricity and other utilities, construction): 8.8%
  • Tertiary (services): 9.3%
• Real GVA growth overall: 7.9% (2025-26), against 7.3% (2024-25) [2].

• Share in nominal GVA, 2025-26 [2]:

  • financial, real estate, IT and professional services, including ownership of dwellings: 27%
  • agriculture, livestock, forestry and fishing: 18%
  • manufacturing: 15%

• Real national income: national income adjusted for price changes.

• Economic growth means a sustained rise in a country's real national income.

• A rise that comes only from higher prices is not growth.

• Class 10 (Sectors of the Indian Economy): compares sectors using real GVA at basic prices, at 2011-12 prices. (Basic prices = value received by the producer, before product taxes and after product subsidies.)

• The chapter notes that the latest data are not used there because the method of estimation changed.
• Lesson: only numbers from the same series can be compared. MoSPI also stresses that the same methods and data sources must be used for both periods in any comparison [3].

7. How prices are removed: single vs double deflation

• Single deflation: one price index (usually the output price) is used to deflate GVA directly.
• Double deflation: output is deflated by an output price index, and inputs by a separate input price index. Then:

• Real GVA = Real output − Real inputs

• Worked example:

• Current year: output ₹120, inputs ₹80, so nominal GVA = ₹40.
• Output prices rose 20% (index 1.2). Input prices did not change (index 1.0).
• Double deflation: real output = 120 ÷ 1.2 = 100; real inputs = 80 ÷ 1.0 = 80; real GVA = ₹20.
• Single deflation: 40 ÷ 1.2 = ₹33.3.

• Single deflation overstates real GVA here, because input prices and output prices moved differently.

• The new series (base 2022-23) [3]:

• Single deflation has been completely removed.
• Double deflation is used in manufacturing and agriculture.
• Single extrapolation is used in other sectors. (This means moving base-year real values forward with volume indicators.)
• More than 300 item-level price indices are used as deflators.
• Separate item-level WPIs are used for output and for inputs in manufacturing.
• The WPI (still on base 2011-12, with its own revision in progress) stays in use for now. The PPI (Producer Price Index, being prepared by DPIIT) will be added once it is released.

8. Base-year revision

• India's GDP base years: 2004-05 → 2011-12 (introduced January 2015) → 2022-23.
• The new 2022-23 series was released on 27 February 2026 [4][3].
• It covers annual and quarterly estimates for 2022-23 to 2025-26.

• GDP of the base year 2022-23 (new series): ₹261.18 lakh crore [4].

• Why revise the base?

• Relative prices, the product mix, technology and data sources all change over time.
• An old base gives too much weight to old goods.

• It also misses new ones, such as digital services and the gig economy.

• How often: MoSPI aims to revise the base about every five years, as recommended internationally [3].

• Why 2022-23 was chosen [3]:
• The base year must be a "normal" year, with no major shocks.
• 2017-18 to 2021-22 were ruled out:
  • GST rollout (2017) needed time to settle
  • COVID-19 hit output (2020-21, 2021-22)

• The choice was recommended by the Advisory Committee on National Accounts Statistics (ACNAS), set up in 2024 with five sub-committees.

• Main changes in the new series [3]:

• Household (informal) sector: now estimated directly every year from the ASUSE (Annual Survey of Unincorporated Sector Enterprises) and the PLFS (Periodic Labour Force Survey), instead of being projected forward from old surveys.
• New data sources:
  • GST data (used to split estimates across states and to cross-check them)
  • PFMS (actual central government spending)
  • e-Vahan (vehicle registrations, used for spending on road transport)
  • MCA filings (MGT-7/7A), used to split multi-activity companies across their businesses
• Supply and Use Tables (SUT): check that total supply of each product equals its total use, i.e. Output + Imports = Intermediate consumption + Final consumption + Capital formation + Exports. This cuts the statistical discrepancy (the gap between GDP measured by production and GDP measured by expenditure).

• Consumption (PFCE): estimated with a mixed method, following COICOP 2018, the international standard list of consumption categories.

• Back series (past GDP recalculated with the new methods so old and new figures can be compared) [3]:

• It is expected by December 2026.

• It will first be recalculated back to the previous base year, then extended to 1950-51 by splicing (joining the old series to the new one).

• Global standards: India follows SNA 2008 (the UN System of National Accounts). It plans to move to SNA 2025 at the next base revision. India also subscribes to the IMF's SDDS (Special Data Dissemination Standard) [3]. Quarterly GDP follows the IMF Quarterly National Accounts Manual (2017) [2].

Prelims Hooks

• Nominal GDP = output at current-year prices. Real GDP = output at base-year (constant) prices. Only real GDP isolates changes in volume.
• GDP deflator = (Nominal GDP ÷ Real GDP) × 100. In the base year it always equals 100.
• Trap: a deflator below 100 (e.g. NCERT's 83.3%) means prices fell since the base year. It does not mean real GDP fell.
• Trap: if nominal GDP rises 10% and prices rise 10%, real growth is about 0% (MoSPI's bicycle example).
• GDP = GVA + taxes on products − subsidies on products. Sector-wise growth is reported as real GVA.
• Current GDP base year: 2022-23, released 27 February 2026 by MoSPI's NSO. The previous series used 2011-12 (introduced January 2015), and before that 2004-05.
• Real GDP growth 2025-26 (PE, June 2026): 7.7%. Nominal growth was 8.9%. Real GVA growth was 7.9%.
• The new series has no single deflation. Double deflation is used in manufacturing and agriculture.
• The Supply and Use Table framework is used to reduce the statistical discrepancy between production-side and expenditure-side GDP.
• India follows SNA 2008. It plans to shift to SNA 2025 at the next base revision. It subscribes to the IMF's SDDS.

Mains Points

• Low deflator and fiscal arithmetic:
• When deflator inflation is very low (about 1.1% in 2025-26), nominal GDP growth (8.9%) is barely above real growth (7.7%).
• Tax buoyancy (how fast tax revenue grows as GDP grows), budget targets and debt-to-GDP paths all depend on nominal GDP.

• So a low deflator can squeeze revenue even during strong real growth. This matters for fiscal planning under GS-III.

• Credibility of the deflator:

• Earlier critics said single deflation using WPI (which contains no services) overstated real growth when input prices fell sharply.
• The 2022-23 series answers this with double deflation, 300+ item-level indices and SUT balancing.

• Gaps remain: the WPI still has base 2011-12, the PPI is still awaited, and services deflators are still weak.

• Why base revision is necessary:

• An outdated base misprices the economy's structure, e.g. digital services, platform and gig work, and the informal sector.
• Annual ASUSE and PLFS data now capture informal activity directly.

• The trade-off: until the back series (due December 2026) is out, growth figures from the old and new series cannot be compared directly.

• Growth vs welfare:

• Real GDP growth measures volume of output, not well-being.
• Sector gaps matter. In 2025-26 primary real GVA grew 3.2% while services grew 9.3%.
• Agriculture still supports a large share of workers, so this gap points to uneven income gains. It links to inclusive growth under GS-III.