By Animesh Raj. Twelve analyses across 293 constituencies and five Assembly cycles. Numbers reported as found.
- Live interactive dashboard: https://wildcraft958.github.io/wb-election-2026
- Twelve-slide PDF carousel:
data/outputs/linkedin_carousel/bengal_2026_analysis.pdf - Cleaned datasets:
data/processed/
This is a portfolio data-engineering and statistics exercise on publicly available election data. It is not partisan commentary, journalism, or a definitive account of the 2026 West Bengal Assembly Election outcome. Every finding here is an illustration of methodology applied to public sources (Wikipedia AC tables, CEO West Bengal SIR PDF, Datameet shapefiles, 2011 Census, hand-curated defection news clippings) and is conditional on those sources plus the documented data caveats below. Headline state numbers (45.4%, 40.8%, 92.93%) are the published ECI values; per-AC numbers are computed from Wikipedia tables and may differ by 1 to 2 percentage points from official tallies. Anyone is welcome to replicate, dispute, or extend any specific number by running the script that produced it (
./run_all.sh).
| Metric | Value |
|---|---|
| BJP seats | 207 (up from 77 in 2021) |
| AITC seats | 80 (down from 215) |
| BJP vote share swing | +7.3 pp (38.2% to 45.4%) |
| AITC vote share swing | -7.1 pp (47.9% to 40.8%) |
| Statewide turnout | 92.93% (highest ever) |
| Voters removed during SIR | ~91 lakh (11.88% of pre-SIR roll) |
| # | Analysis | Key result |
|---|---|---|
| 02 | District-level swing | BJP gained vote share in 23 of 24 districts. Three swung over 30 pp (Purulia, Bankura, Purba Bardhaman). |
| 03 | Turnout regression (OLS) | Slope +0.53, R² = 0.34, p < 0.001. Where turnout fell, TMC fell harder. |
| 04 | SIR deletion impact | In 27 of 207 BJP wins, estimated voter deletions exceed the BJP margin. Spearman ρ = +0.39, p < 0.001. |
| 05 | Opposition fragmentation | In 68 of 207 BJP wins (33%), 3rd-place-onward votes alone exceed BJP margin. |
| 06 | Spatial autocorrelation | Moran's I = 0.46, p = 0.001. Wave clustered in Jangalmahal; cold spot in Murshidabad-Malda. |
| 07 | Random Forest + SHAP | 88% CV accuracy. 2021 baseline vote shares dominate predictions. |
| 08 | K-means typology (k=5) | Five archetypes: Jangalmahal Sweep, Minority Fortress, SIR Battlegrounds, Urban Flippers, Mixed. |
| 09 | OLS margin model | Adjusted R², coefficient table, residual diagnostics. |
| 10 | DiD on SIR exposure | +9.2 pp gap; parallel-trends fail (5.02 pp/yr gap), so descriptive, not causal. |
| 11 | 5-cycle panel 2006-2026 | 85 ACs voted Left → TMC → BJP across the three cycles. |
| 12 | Defection network | Welch t-test p = 0.33; defections did not, on their own, predict where the wave broke. |
A booth-level Form-20 + Benford's Law analysis is deferred until CEO West Bengal publishes Form-20 (expected June 2026). Parser scaffold lives in scripts/07_parse_form20.py.
python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
playwright install chromium # only used by future scrapers
./run_all.shPipeline regenerates data/processed/master.csv, the figures under data/outputs/, and the LinkedIn carousel PDF.
To open the dashboard locally:
cd dashboard && python -m http.server 8765
# open http://localhost:8765- Headline state numbers (45.4% / 40.8% / 92.93%) are the published ECI values.
- Per-AC vote shares come from Wikipedia AC tables, which expose only the top two candidates per seat. Per-AC totals therefore under-attribute votes to 3rd-place candidates by 1 to 2 pp on average. The relative pattern (correlation, regression, clustering) is unaffected.
- AC-level SIR deletion totals are estimated by allocating the published state aggregate proportionally to polling-station counts. The voter-level deletion lists themselves are captcha-gated on the ECI portal.
- Falta (AC 144) is excluded; repoll on 21 May 2026, results 24 May.
- DiD's parallel-trends assumption fails on the 2006-2021 panel, so the +9.2 pp DiD estimate is reported as descriptive, not causal.
- ECI 2026 results (Wikipedia mirror): https://en.wikipedia.org/wiki/2026_West_Bengal_Legislative_Assembly_election
- ECI 2006/2011/2016/2021 (Wikipedia): same domain, year-based URLs
- CEO West Bengal SIR draft electorate PDF: https://ceowestbengal.wb.gov.in/SIR
- Datameet AC shapefile (CC-BY 4.0): https://github.com/datameet/maps/tree/master/assembly-constituencies
- 2011 District Census Handbook district-level demographics
- Hand-curated TMC/BJP defections list (cross-checked against AC numbers):
data/raw/defections/defections_seed.csv
Code under MIT. Data under the licenses of the underlying sources (Datameet CC-BY 4.0, Wikipedia CC-BY-SA 4.0, ECI public-record tabulations, Census of India public release).