BIAS & TIMING RISK DOCUMENTATION
1. LOOK-AHEAD BIAS: Avoided — CPI surprise computed using only data available on release date. No future data used in any calculation.
2. SURVIVORSHIP BIAS: Minimal — indices (NASDAQ, Dow Jones, Russell 2000) are broad market indices not individual stocks. Index composition changes over time but this is standard practice.
3. SELECTION BIAS: Acknowledged — IWM used as Russell 2000 proxy. ETF closely tracks index with minimal tracking error.
4. CALENDAR/TIMING RULE: CPI release date used as event timestamp. All 117 dates confirmed as weekdays. Trading day rule applied via Inner Join — only dates with price data retained.
5. REVISION BIAS: CPIAUCSL from FRED may be revised after initial release. We use downloaded
data which may reflect revised figures.
