Index of Core Industries

Purpose and compiler

• The Index of Core Industries (ICI) tracks output from India’s most vital infrastructure sectors.
• It is compiled and released by the Office of the Economic Adviser (OEA), under the DPIIT, Ministry of Commerce & Industry.

The July 2026 revision

• On 20 July 2026, the OEA released a revised ICI series with a new base year of 2022-23.
• This revision added Iron Ore as a core industry, taking the total from 8 to 9.
• GDP, WPI and IIP now all share 2022-23 as a common base year.

Weights under the 2022-23 base

• “Eight” is now a stale label.
• Its old name lingers in exam material and habit, even though the basket has changed.

Timeline of base years

• 1980-81: the ICI is first compiled, with this year as its base.
• 1993-94: the base year is revised.
• 2004-05: the base is revised again. Fertilizers and Natural Gas are added, bringing the count to 8.
• 2011-12: the base aligns with the IIP’s own base year. Refinery Products overtakes Electricity as the highest-weighted industry.
• 20 July 2026: base 2022-23. Iron Ore is added, making 9. Electricity regains the top weight.

Before the 2004-05 series

• The index basket had only 6 industries.
• They were coal, cement, finished steel, electricity, crude petroleum and refinery products.

The weight order has flipped over time

• 2004-05 base (in force at the time of the UPSC 2015 prelims): Electricity carried the highest weight, at 10.32%.
• Steel followed at 6.68%, and Refinery Products at 5.94%.
• 2011-12 base: the ranking flipped. Refinery Products became the highest, at 28.04%, with Electricity second at 19.85%.
• The 8 core industries carried a combined weight of 40.27% in the IIP under this series.
• 2022-23 base: the order flipped back. Electricity is again the highest, at 30.93%, in the nine-industry index.

Methodology changes in 2026

• The Steel Index now uses gross production data, replacing the earlier net-production basis.
• In the Coal component, only Raw Coal is retained.
• The Index is calculated using Laspeyres’ formula, a weighted arithmetic mean of quantity relatives.

Pattern

• Each base-year revision (1980-81, 1993-94, 2004-05, 2011-12, 2022-23) has tried to keep the basket matching the real economy.
• Adding Iron Ore, rather than removing an older industry, shows how India’s growth priorities have shifted.
• Raw-material security for steel and manufacturing is now significant enough to have its own tracked line.

Why the methodology shift matters

• Switching Steel from net to gross production is subtle but real.
• It can shift reported growth figures even without any change in factory output.
• ICI, IIP, WPI and GDP sharing a 2022-23 base is a deliberate design choice.
• It makes headline indicators easier to compare against each other, not just against their own past.

Related reading

• Industry in the Indian Economy, the ministry context the OEA and DPIIT sit within.
• India Industrial Output, May 2026, for the IIP side.

20 July 2026: first release under the new series

• The OEA published its first press release under the new ICI series, base year 2022-23.
• Provisional data showed the ICI grew 5.0% year-on-year in June 2026. (Source: PIB.)

20 July 2026: recalculated back series

• Alongside the June 2026 figure, the OEA released a full back series.
• It recalculates ICI data under the new base year from April 2023 through May 2026, a 38-month span. (Source: PIB.)

22 June 2026: last release under the old series

• Under the old series (base year 2011-12=100), the combined ICI grew 0.5% (provisional) in May 2026 over May 2025.
• Steel, Cement and Electricity posted positive growth.
• Coal, Crude Oil, Natural Gas, Refinery Products and Fertilizers all declined.
• This was the last release before the July 2026 switch to the new base year. (Source: PIB.)