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-Carmignac Project 
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+# Carmignac — Data Repair Pipeline
+
+Registrar Account ID repair for AUM and Flows data.  
+Carmignac × ENSAE Data Challenge 2025.
+
+---
+
+## Problem
+
+AUM and Flows tables must satisfy the stock-flow identity for every `(account, ISIN, month)`:
+
+```
+Q(t-1) + F(t-1→t) = Q(t)
+```
+
+In practice this identity is violated because Registrar Account IDs change over time — a single distributor may appear under different codes at different dates. The pipeline detects these ruptures, scores data quality, and resolves identity changes through targeted *surgeries*.
+
+---
+
+## Files
+
+| File | Role |
+|------|------|
+| `carmignac_diagnostics.py` | Step 0 — market-level audit, broken months, error account |
+| `carmignac_repair.py` | Steps 1–3 — universe, score propagation, surgery |
+| `carmignac_branch.py` | Apply the repaired mapping to the raw AUM file |
+| `carmignac_analysis.py` | HTML report from pipeline outputs |
+
+---
+
+## Usage
+
+Run in order:
+
+```bash
+# 1. Diagnostics (produces broken_months CSV fed into repair)
+python carmignac_diagnostics.py \
+  --aum   raw_AUM.csv \
+  --flows raw_flows.csv
+
+# 2. Repair
+python carmignac_repair.py \
+  --aum   raw_AUM.csv \
+  --flows raw_flows.csv \
+  --broken-months carmignac_broken_months.csv
+
+# 3. Apply mapping to raw AUM
+python carmignac_branch.py \
+  --aum     raw_AUM.csv \
+  --mapping carmignac_mapping.csv \
+  --surgery carmignac_surgery_log.csv
+
+# 4. Analysis report
+python carmignac_analysis.py \
+  --error-account-isin carmignac_error_account.csv \
+  --error-account-agg  carmignac_error_account_agg.csv
+```
+
+---
+
+## Outputs
+
+| File | Content |
+|------|---------|
+| `carmignac_broken_months.csv` | (ISIN, month) pairs where the aggregate stock-flow equation is broken |
+| `carmignac_error_account.csv` | Cumulative unresolved residuals per ISIN |
+| `carmignac_error_account_agg.csv` | Same, aggregated over all ISINs |
+| `carmignac_scores.csv` | Data quality score σ_r(t) for every (account, month) |
+| `carmignac_mapping.csv` | Canonical identity mapping (date, reg_orig, reg_used) |
+| `carmignac_surgery_log.csv` | All surgery operations with Jaccard, score gain, lookback |
+| `AUM_repaired.csv` | Full AUM with corrected Registrar Account IDs |
+| `AUM_paths.csv` | Universe accounts with their identity path over time |
+| `carmignac_diagnostics.html` | Interactive diagnostic report |
+| `carmignac_report.html` | Interactive repair & surgery report |
+
+---
+
+## Key parameters
+
+| Parameter | Value | Role |
+|-----------|-------|------|
+| `MIN_AUM_EUR` | 5 M€ | Universe threshold at t* |
+| `ALPHA` | 5% | Reconciliation tolerance |
+| `SCORE_DROP_THRESHOLD` | 0.5 | Surgery trigger |
+| `MIN_JACCARD` | 0.3 | ISIN portfolio pre-filter |
+| `MAX_SURGERY_LOOKBACK` | 6 months | Max search window for predecessor code |
+| `SYMMETRY_ATTENUATION` | 0.05 | Error discount for symmetric transfers |
+| `BROKEN_MONTH_ATTENUATION` | 0.20 | Error discount for broken market months |
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