# Contract — F1-conf-01

Question: 12-month growth of CPIAUCSL (SA) for each month 2001-01..2026-09 and summaries. Estimand: g_t = 100*(P_t/P_{t-12} - 1), P from the most recent vintage covering the month (2026-10-28 for 2014-01..2026-09, 2016-07-15 otherwise). Summaries: mean over window, sub-period means 2001-01..2013-12 and 2014-01..2026-09, g at 2014-06, 2016-07, 2020-05, 2022-06, 2026-09, max/min and months. Meaningful under: vintages are faithful copies; mixing vintages across the 2013/2014 seam is accepted by the task rule. Outputs: out/results.json (keys per TASK.md table), out/analytic.csv, out/exclusions.csv, out/report.md, out/analysis.py, out/claims.json. Information rules: most-recent-vintage rule; no interpolation/imputation; missing g reported & counted; only data/. Invalidity: using the hand-assembled file (contains errors), imputing the missing 2025-10 level, using the 2016 vintage in 2014-2016.