Base year revision
In one line: A base year revision updates a price index's reference year, basket and weights so that it reflects the current economy.
What changed in the WPI
The base moved from 2011-12 to 2022-23. Items rose from 697 to 957. Weights now use gross value of output instead of net traded value. Solar, wind and nuclear power were added to electricity. Crude petroleum and natural gas moved to fuel and power. Missing prices are now filled by targeted mean imputation instead of carrying forward the last price, and elementary indices use a short-term formula.
Comparing old and new
Linking factors join the two series: 1.53 for all commodities, 1.71 for primary articles, 1.65 for fuel and power and 1.44 for manufactured products. The Office of the Economic Adviser advises caution in comparing across series.
Where to go next
- Wholesale Price Index
- Producer Price Index
Base year revision in the news
- Core sector grows 7.9% in September 2026, fastest since the new series began 22 October 2026
Why statistical indices are moved to a newer reference year.
- Wholesale inflation rises to 11.39% in September, led by fuel and power at 25.85% 15 October 2026
Why the basket and base change, and what to watch when comparing.
Previous-year questions on this
- 2024 · GS3 · 10 marks What are the causes of persistent high food inflation in India? Comment on the effectiveness of the monetary policy of the RBI to control this type of inflation.
- 2023 · GS3 · 10 marks Faster economic growth requires increased share of the manufacturing sector in GDP, particularly of MSMEs. Comment on the present policies of the Government in this regard.
- 2022 · GS2 · 15 marks Besides the welfare schemes, India needs deft management of inflation and unemployment to serve the poor and the underprivileged sections of the society. Discuss.
- 2020 · Prelims Consider the following statements: 1. The weightage of food in Consumer Price Index (CPI) is higher than that in Wholesale Price Index (WPI). 2. The WPI does not capture changes in the prices of…
- 2015 · Prelims In the Index of Eight Core Industries, which one of the following is given the highest weight? (a) Coal Production (b) Electricity generation (c) Fertilizer Production (d) Steel Production