# Contract — F2-conf-02

Question. Is the memo's claim that the OLS slope of y on x is significant at 5% supported once uncertainty accounts for serially correlated (AR(1), rho~0.7) disturbances and a persistent regressor? Estimand. β in the linear projection y_t = α + β x_t + u_t (full sample OLS, 400 months). Meaningful under stationarity / weak dependence so that OLS is consistent for the projection coefficient and a HAC long-run variance estimator is consistent. Uncertainty. Newey–West (Bartlett kernel) HAC SE with a justified bandwidth; t, two-sided p (normal reference), 95% CI = beta ± 1.96·se_hac. Outputs. out/results.json keys: 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). Information rules. Only data/series.csv and data/memo.md; memo numbers are to be reproduced/checked, not taken as given. Invalidity. Missing/duplicated/gapped months, non-numeric values, or a non-reproducible memo baseline would need reporting; nonstationarity would undermine HAC inference.