New GDP series with base 2022-23 and double deflation

The new GDP series and double deflation: what happened?

GDP numbers move markets and policy, so a change of method invites suspicion. The new series changed the base year and the way manufacturing output is deflated. Several figures looked odd at first sight, and MoSPI’s answers teach a good deal of national accounts along the way.

• The updated series uses the new Output Producer Price Index and Banking Services Price Index, both based on 2022-23.
• The IMF calls double deflation the preferred method for calculating GDP in volume terms.
• Mining showed real GVA of -2.4% but nominal GVA of 22.3%, because crude oil, gas and metal ore prices jumped.
• The implicit GDP deflator was 2.5%, while CPI was 3.9% and WPI over 9%.
• At final estimates, the discrepancy between production and expenditure estimates is very small or zero, as for 2022-23 and 2023-24.

What is double deflation?

• Output and intermediate consumption are deflated separately.
• Real GVA = real output minus real intermediate consumption.
• If input prices rise faster than output prices, nominal GVA can grow more slowly than real GVA.
• Then the implicit GVA deflator turns negative even though all prices are rising.
• A negative manufacturing deflator does not mean manufacturing prices fell.

How does the PIB illustration work?

Nominal GVA grows 12%, real GVA 17.5%: the implicit deflator is negative.

Why does the GDP deflator differ from CPI and WPI?

• CPI covers a basket of household consumption at the consumer’s end.
• WPI covers bulk commodities, raw materials and manufactured goods, excluding services.
• The implicit GDP deflator is the ratio of GDP at current prices to GDP at constant prices and covers the whole economy, including services.
• It is derived from more than 300 item-level price deflators.

How did last year’s Q1 GDP get revised?

How is quarterly GDP built?

1. Previous-year benchmark taken from the latest comparable series
2. High-frequency indicators (crops, cement, steel, vehicle sales) show movement
3. Constant-price estimates prepared; manufacturing by double deflation
4. Current-price estimates derived with price indices
5. Estimates revised as fuller data arrive

Why does the new GDP series and double deflation matter?

What are the challenges in the new GDP series and double deflation?

• Negative or volatile deflators can confuse users during commodity price shocks.
• Large statistical discrepancies in early estimates invite doubt.
• Frequent revisions make old and new numbers hard to compare.

What should be done next on the new GDP series and double deflation?

• Further revisions as comprehensive data arrive.
• Discrepancies to shrink by the final estimates.
• Wider public communication of methods, as in this FAQ.

What can Prelims ask on the new GDP series and double deflation?

• New GDP series: base year 2022-23 (released with new PPI and Banking Services Price Index).
• Double deflation: output and inputs deflated separately; used for manufacturing.
• Implicit GDP deflator = GDP at current prices / GDP at constant prices.
• WPI excludes services; CPI tracks household consumption.

How to write about the new GDP series and double deflation in Mains

Practice question (10 marks, 150 words): What is double deflation? Explain how it can produce a negative GVA deflator, and why base-year revisions are needed in national accounts.

• Intro: new series, base 2022-23.
• Double deflation: definition with the PIB illustration.
• Negative deflator: input prices rising faster than output prices.
• Base-year revision: changing structure and relative prices.
• Conclusion: compare within one series; revisions are normal.