# Contract (F2-conf-02)

• Question: is the memo's claim that the OLS slope of y on x is significant at 5% supported once SEs account for serially correlated errors?
• Estimand: beta in linear projection y_t = a + b x_t + u_t, OLS on full sample (400 months). Meaningful as a projection coefficient under stationarity; inference valid under weak dependence via HAC (Newey-West, Bartlett kernel), bandwidth justified.
• 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. claim restating memo conclusion).
• Info rules: only data/series.csv and data/memo.md; memo numbers may be reproduced, not taken as given.
• Invalidating: missing/gapped data, inability to compute HAC; choosing bandwidth to target a conclusion.