# Contract (F2-smoke-01)

• Question: linear association between y and x in a firm panel (synthetic data).
• Estimand: population slope beta of the linear projection y = a + b x + e; meaningful under finite second moments, observations independent across firms but arbitrarily dependent within firm (common firm shock). Inference requires reasonably many clusters (here 50).
• Outputs: out/results.json (task_id, beta_hat, alpha_hat, se_ols, se_cluster, beta_ci_low, beta_ci_high, n_analysed, n_clusters, 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.
• Information rule: only data/panel.csv.
• Invalidity: missing/unparseable data, too few clusters, no variation in x, any use of external information.