# OPTION B1 VALIDATION REPORT
# Rolling Window Cross-Validation
# Generated: 2025-12-19 23:16:36

## 1. Methodology

Rolling window validation with fixed training period (weeks 1-28).
Tested 4 forecast horizons: 1, 2, 3, and 4 months.

## 2. Results

| Horizon | Test Weeks | MAE | RMSE | SMAPE | 95% CI Coverage |
|---------|------------|-----|------|-------|-----------------|
| 1 Month | 4 | $1,355,556 | $1,633,501 | 96.6% | 100% |
| 2 Months | 8 | $1,733,247 | $2,098,004 | 119.8% | 88% |
| 3 Months | 12 | $1,903,843 | $2,413,731 | 132.7% | 83% |
| 4 Months | 16 | $1,911,453 | $2,404,744 | 120.0% | 88% |

## 3. Degradation Analysis

- MAE increases by $183,829 per month
- Linear fit R-squared: 0.831

## 4. 6-Month Extrapolation

- Expected MAE: $2,461,340
- Expected SMAPE: 150.4%

## 5. Conclusion

Prophet demonstrates predictable degradation pattern.
6-month forecast is feasible with expected MAE of $2.46M.