# Contract — F2-conf-02
**Question.** Is the memo's claim that the OLS slope of y on x (monthly, 400 obs) is significant at 5% supported once the standard error accounts for serially correlated disturbances?
**Estimand.** β in the linear projection y_t = α + β x_t + u_t, OLS on full sample. Meaningful under stationarity / weak dependence of (x_t, u_t) with E[x_t u_t]=0 (projection definition). Uncertainty: Newey–West (Bartlett) HAC SE, justified bandwidth.
**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. a claim restating the memo's conclusion with verdict as status).
**Information rules.** Only data/series.csv and data/memo.md. Memo numbers are to be reproduced/checked, not taken as given.
**Invalidity.** Missing/corrupt data, gaps in months, non-numeric values; inability to reproduce; HAC SE with unjustified bandwidth. Decision rule: memo claim supported iff |t_hac| > 1.96 (p_hac < 0.05, normal reference).