Eight core industries

Indian Economy glossary

Also called: Core sector, Core industries, Index of Eight Core Industries, ICI · Topic: Industrial Policy, Public Sector, MSMEs and Disinvestment · NCERT: Class 11, Ch 7 "Index Numbers"

Meaning

The eight core industries are coal, crude oil, natural gas, refinery products, fertilisers, steel, cement and electricity. Their monthly output is tracked by the Index of Eight Core Industries (ICI), which is compiled by the Office of the Economic Adviser, DPIIT (Department for Promotion of Industry and Internal Trade, under the Ministry of Commerce and Industry). Together these industries make up 40.27% of the Index of Industrial Production (IIP), which uses a 2011-12 base.

They matter because most other industries depend on them for fuel, power and basic materials. When core output rises or falls, the rest of industry usually follows. That is why the ICI is watched as an early signal of industrial health.

Formula: Change in ICI (%) = Σ (weight of each industry × growth of that industry) ÷ 100

Explanation

What the index measures

  • Index number: a single figure that shows how a group of values changes compared with a base period. The base year is the reference year, and its value is set at 100. (NCERT Class 11, Index Numbers.)
  • The ICI is a weighted index of output. Each industry counts in proportion to its weight, so bigger industries move the index more.
  • It is monthly, so it is a quick guide to how basic industry is doing.
  • Why these eight are called "core":
  • Coal, crude oil, natural gas, refinery products, electricity → give energy to every factory, farm and home.
  • Steel, cement → used in construction and infrastructure.
  • Fertilisers → a key input for agriculture.

The eight components and their weights (base 2011-12)

Rank Industry Weight
1 Refinery products 28.04 (highest)
2 Electricity 19.85
3 Steel 17.92
4 Coal 10.33
5 Crude oil 8.98
6 Natural gas 6.88
7 Cement 5.37
8 Fertilisers 2.63 (lowest)
  • These weights add up to 100. They are weights inside the ICI, not inside the IIP.
  • Memory aid (in descending order): Refinery, Electricity, Steel, Coal, Crude, Gas, Cement, Fertilisers.
  • Energy is most of the index: refinery products, electricity, coal, crude oil and natural gas together weigh 74.08. So the ICI is largely an energy index.

Worked examples: why weights matter

  • Example 1: one industry grows alone
  • Refinery output grows 10% and all others grow 0%.
  • ICI change = 28.04 × 10 ÷ 100 = 2.8%.

  • If fertilisers grow 10% instead and all others grow 0% → ICI change = 2.63 × 10 ÷ 100 = only 0.26%.

  • Example 2: mixed month (illustrative growth rates)

  • Refinery −2%, electricity +6%, steel +8%, the other five 0%.
  • Refinery: 28.04 × (−2) = −56.08
  • Electricity: 19.85 × 6 = 119.10
  • Steel: 17.92 × 8 = 143.36

  • Total = 206.38 → ÷ 100 = ICI up about 2.06%

  • Lesson: a drop in a heavy industry (refinery products) can hide good growth elsewhere. Strong growth in a light industry (fertilisers) hardly moves the index.

What makes the index rise or fall

  • Demand from construction and infrastructure → more roads and buildings → more steel and cement output.
  • Power demand → hot summers and more factory activity → more electricity and coal output.
  • Oil and gas conditions → refinery runs, crude production and gas output change with demand and supply.
  • Farm cycle → fertiliser output follows the sowing seasons, but its effect on the index is small because its weight is only 2.63.

In India

  • Who compiles it: the Office of the Economic Adviser, DPIIT, Ministry of Commerce and Industry.
  • Who compiles the IIP: the NSO (National Statistical Office), MoSPI (Ministry of Statistics and Programme Implementation). The two indices come from different ministries. This is a common exam trap.
  • Link to IIP: the eight core industries make up 40.27% of the IIP (base 2011-12). A weak core month usually means a weak IIP month.
  • Base year: the current weights use 2011-12. A base revision is due (verify current).
  • Policy link: the manufacturing push (Make in India from Sept 2014, PLI from 2020-21, the National Manufacturing Mission in Budget 2025-26) needs cheap and steady power, fuel, steel and cement. The core sector supplies these inputs.

Don't confuse with

  • IIP (Index of Industrial Production): measures all industry (mining, manufacturing and electricity) and is compiled by NSO-MoSPI. The ICI covers only eight industries and is compiled by the Office of the Economic Adviser, DPIIT.
  • Weight in IIP vs weights in ICI: 40.27% is the share of all eight industries in the IIP. Figures such as 28.04 (refinery) are weights inside the ICI, and they add up to 100.
  • Core inflation: this is inflation that leaves out volatile items such as food and fuel. It is about prices. The core sector index is about output. The two are unrelated despite the shared word "core".
  • Infrastructure sector / industrial corridors: these are broader ideas about roads, ports, logistics and zones (e.g. PM GatiShakti). The "core sector" is a fixed list of eight industries used for measurement.

Prelims Hooks

  • The eight core industries are coal, crude oil, natural gas, refinery products, fertilisers, steel, cement and electricity.
  • The Index of Eight Core Industries is compiled by the Office of the Economic Adviser, DPIIT (Ministry of Commerce and Industry). It is not compiled by NSO. The IIP is compiled by NSO-MoSPI.
  • Core industries make up 40.27% of the IIP (base 2011-12).
  • Highest weight: refinery products (28.04). Lowest weight: fertilisers (2.63). Order: Refinery > Electricity > Steel > Coal > Crude > Gas > Cement > Fertilisers.
  • Trap: steel (17.92) weighs more than coal (10.33), and cement (5.37) weighs more than fertilisers (2.63). Electricity (19.85) is second, not first.
  • The ICI is a monthly, weighted output index. ICI change = Σ (weight × growth) ÷ 100.

Mains Points

  • Early warning for the manufacturing push: the core sector feeds every factory.
  • Weak core growth → costly or scarce power, steel and cement → higher costs for manufacturers, including PLI firms.

  • So the goals of NMP 2011 (manufacturing at 25% of GDP) and the National Manufacturing Mission (Budget 2025-26) depend on a strong core sector.

  • An energy-heavy index: fuel and power industries weigh 74.08 of the ICI's 100.

  • The headline number can move because of oil and power trends even when construction or farm inputs are doing well.

  • Analysts should read the growth of each industry, not only the headline figure.

  • Old base year: the weights still use 2011-12, and a revision is due (verify current).

  • An old base can misstate newer energy sources and changes in demand.
  • Timely base revision, and keeping it in line with the IIP, improves the data used for policy.

Related concepts

Read more

Sources

  1. 1Class 11, Ch 7 "Index Numbers" (primary)