# Contract (F2-conf-02)
- Question: is the memo's claim "slope significant at 5%" supported when uncertainty accounts for serially correlated errors?
- Estimand: β in the linear projection y_t = α + β x_t + u_t, OLS full sample (400 months). Meaningful under stationarity/weak dependence; inference via HAC (Newey–West, Bartlett kernel) SE, asymptotic normal reference.
- Outputs: out/results.json (task_id, beta_hat, alpha_hat, se_iid, rho_resid, se_hac, hac_lags, t_hac, p_hac, beta_ci_low, beta_ci_high, memo_claim_supported, n_analysed, feasibility, feasibility_reason, data_issues, n_input_rows, random_seed), out/report.md (Question; Data and exclusions; Method; Results; Uncertainty; Limitations and open issues), out/analysis.py, out/claims.json (incl. memo-claim verdict).
- Info rules: only data/series.csv and data/memo.md; memo numbers reproduced, not taken as given.
- Invalid if: data missing/corrupt, non-reproducible script, SE not robust to autocorrelation.