# Contract (P0)
**Question:** Brock–Mirman optimal growth, log utility, y' = (y-c)^alpha, full depreciation. Compare closed-form policy/value with VFI on prescribed log grid.
**Estimands:** closed-form c(y)=(1-alpha*beta)y at y=0.5,1,2; VFI policy at same points (linear interpolation between grid nodes); max abs policy error; V(1) closed form and VFI; savings rate alpha*beta; contraction modulus (beta, Blackwell sufficient conditions on bounded grid problem).
**Assumptions:** log utility, Cobb-Douglas, full depreciation, interior solution, 0<alpha<1, 0<beta<1.
**Outputs:** out/results.json (keys per TASK.md table), out/report.md (6 sections), out/analysis.py, out/claims.json; plus protocol state files and out/exclusions.csv.
**Info rules:** only data/model.csv; prescribed grid (400 log-spaced points in [0.05,5]), tolerance 1e-8; numerical policy from VFI only; deviations into data_issues.
**Invalidity:** missing parameters, infeasible grid (no feasible choice at some node), non-convergence, using closed form to construct numerical policy.