# Contract — F2-conf-02

Question. Does the memo's claim that the OLS slope of y on x is significant at 5% survive when uncertainty accounts for serially correlated errors? Estimand. β in the linear projection y_t = α + β x_t + u_t (full sample, OLS). Meaningful as a projection coefficient under stationarity/weak dependence of (x_t, u_t); HAC inference requires weak dependence and a bandwidth growing slowly with T. 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 (6 sections), 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 used only for comparison. Invalidity. Missing/irregular data that cannot be handled; inability to compute HAC; using memo numbers as given.