TeX 55.1%
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1<!-- Author: Simon-Pierre Boucher — simon-pierre.boucher@uqo.ca -->2# Phase 0 — evidence-based research plan (2026-10-21)34## What exists5- **Data**: Vrai Prix production SQLite (M3U96a), 769,995 registry transactions 2021-01-04 → 2026-10-07, geocoded,6 provider type, matched to the MAMH assessment roll (3.75 M units: CUBF, units, link, floor/lot area, year, storeys,7 neighbourhood unit, values). Four earlier extractions (Aug 6, Aug 9, Oct 10, Oct 17 2026) allow measuring arrival lags.8- **Prior code**: QWHPI (PhD/recherche/QWHPI) — a working monthly/weekly hedonic index engine (RTD + Huber + hierarchical9 Kalman shrinkage), used here as benchmark K and as a source of lessons (building-type backfill, time-correlated10 missingness, mean splice).11- **Boundaries**: SDA V2026-07 (municipality, MRC, region, metropolitan community, borough); MAMH register.12- **Tooling**: Python 3.14 with polars, duckdb, pyarrow, statsmodels, pyfixest, lightgbm, geopandas; LaTeX (latexmk).1314## What is missing / infeasible15- No deed-type, arm's-length, financing, listing, bedroom/bathroom, renovation or image data.16- Roll characteristics are a single current vintage (post-sale for most sales).17- Statistics Canada CMA boundaries blocked (bot check) → CMM/CMQ used.18- No independent monthly municipal index exists for Quebec to validate against; external comparison limited to19 province/CMA-level public indices (to be obtained and harmonised in Phase 6, if accessible).2021## Phases (status tracked in docs/research_log.md)221. Data inventory, provenance, cleaning — scripts 01–06 (done 2026-10-21).232. Benchmarks A–K at province × type and region × type; liquid municipalities for the feasible subset.243. SHARP-HPI: robust hedonic with fine-location FE and smoothly time-varying quality prices → nested hierarchical25 local-level state-space on quality-adjusted residual means (province → region → MRC → municipality) with26 empirical-Bayes calibrated innovation variances and an observable reliability score; adaptive window / pooling.274. Monte Carlo on synthetic Quebec-like markets (known latent paths), including counterexamples.285. Full monthly panel 2021-01 → 2026-10 (partial), schema of §17, parquet + CSV.296. Validation: forward-chaining backtests, repeat-sales agreement, placebo & composition shocks, real-time vintages30 and revision statistics, ablations, aggregation sensitivity.317. Manuscript (LaTeX, UQO template), figures/tables generated from results, reproducibility audit.32