Interactive three-armed demographic glyphs for 23 Indian states, showing age structure, national population weight and cohort momentum from 2011 to 2036, alongside the Lok Sabha seat reallocation that population-proportional delimitation would produce.
The delimitation fingerprint
Every state has an age shape. The states that finished the demographic transition are the ones about to lose seats for it.
Lok Sabha seats have been frozen on the 1971 census since 1976, so that states which brought fertility down would not be penalised for it. The freeze expires in 2026. Drag the year: even on 2011 population the south is already seventeen seats short of proportional. By 2036 it is twenty-nine, and four Hindi-belt states are thirty-eight ahead.
National weight — share of all Indians in that age group who live here.
Momentum — size of each age group against the same group in 2011.
Each arm runs 0–4 at the centre out to 80+ at the tip.
Two readings
The states that complied are being punished
National family-planning policy asked every state to bring fertility down. Tamil Nadu, Kerala, Andhra and Karnataka did it — through female schooling, public health systems and late marriage — and reached replacement fertility between 1988 and 2005. Their reward, if seats follow population, is to lose 29 of them between five states while four Hindi-belt states gain 38. The 1971 freeze was the promise that this would not happen; it expires in 2026.
Seats follow people, and people are real
A voter in Bihar currently shares an MP with roughly three times as many people as a voter in a small northern state, and considerably more than one in Kerala. Freezing the 1971 ratios permanently means an Indian born in Patna counts for less than an Indian born in Thiruvananthapuram, for the whole of their life, because of a policy choice made before they existed. Under-representing a young, poor, fast-growing population is not an obviously just answer to the problem either.
How this is built
- Population data — Registrar General of India / National Commission on Population, Population Projections for India and States 2011–2036 (Technical Group on Population Projections, July 2020), Table 18: projected population by age and sex, 17 five-year age groups, six snapshots. No figure here is estimated or interpolated by me.
- Projection units — the report projects 23 units covering 99.6% of India's 2011 population. The seven north-eastern states other than Assam are projected as one combined unit and are shown that way here. Goa, Chandigarh, Puducherry, Lakshadweep, Andaman & Nicobar and Dadra & Nagar Haveli / Daman & Diu are not in the projection set; their 8 Lok Sabha seats are held fixed and excluded from the pool. Jammu & Kashmir is projected on its 2011 boundary and so includes Ladakh; the two seats are combined accordingly.
- Source erratum — page 181 of the report prints Uttarakhand's Table 18 under the heading "PUNJAB". Corrected here against the surrounding T-17 pages and Table 21 totals.
- Seat allocation — the 535 seats belonging to projected units are reallocated by the largest-remainder (Hare quota) method on projected total population. Actual delimitation would also apply constitutional floors, reserved-seat rules and intra-state redistricting; this is the arithmetic baseline, not a forecast of the Commission's output.
- Momentum arm scale — clipped at ±100%. Bars that run past the clip carry a notch at the tip and the tooltip reports the true value. The largest uncapped value in the dataset is +1,488% (the 80+ cohort in a fast-ageing state), which would flatten every other bar on a shared linear scale. About 11% of bars across the whole dataset are clipped, almost all of them in the 65+ groups where an open-ended top category and a low 2011 base make the ratio unstable.
- Shared scales — all three arms use the same scale across every state and every year, so glyphs are directly comparable. Nothing is rebased per state.
- Boundaries — Datameet maps (Admin2), which follows Survey of India and shows the full claimed extent of Jammu & Kashmir.