{"abstract":"An ATT request silently averages untreated potential outcomes.","category":"Causal analysis data contracts","checks":6,"contract":"Rows [treated,y0,y1] contain both synthetic potential outcomes. target is ATT or ATE; return the target average y1-y0, None for an empty target.","contract_signature":"rows, target","evaluation_group":"model-13dbe6a165f245cc","failed_approach":"Selecting by positive individual effect substitutes outcome response for target membership.","family":"z-causal_inference-estimand-target","id":"FA-12646","implementations":{"attempt":{"sha256":"7c03f25e16ea4e0346fe6b768637de0f83aab0a3158b7f90f2ad25e6ee22baf8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows, target):\n    chosen = [r for r in rows if target == 'ATE' or r[2] > r[1]]\n    return sum(r[2]-r[1] for r in chosen)/len(chosen) if chosen else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ATT membership', solve([[1,0,2*N],[0,0,8*N]], 'ATT'), 2*N)\ncheck('ATE', solve([[1,0,2*N],[0,0,8*N]], 'ATE'), 5*N)\ncheck('negative treated', solve([[1,3*N,N],[0,0,N]], 'ATT'), -2*N)\ncheck('no treated', solve([[0,0,N]], 'ATT'), None)\ncheck('empty', solve([], 'ATE'), None)\ncheck('null effect treated', solve([[1,N,N]], 'ATT'), 0)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"f45c629b3a6f208fabf2c13e6122cd75a332f79842f95f9e517a8d84ee4faeee","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows, target):\n    return sum(r[2]-r[1] for r in rows)/len(rows) if rows else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ATT membership', solve([[1,0,2*N],[0,0,8*N]], 'ATT'), 2*N)\ncheck('ATE', solve([[1,0,2*N],[0,0,8*N]], 'ATE'), 5*N)\ncheck('negative treated', solve([[1,3*N,N],[0,0,N]], 'ATT'), -2*N)\ncheck('no treated', solve([[0,0,N]], 'ATT'), None)\ncheck('empty', solve([], 'ATE'), None)\ncheck('null effect treated', solve([[1,N,N]], 'ATT'), 0)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Finite, fully specified synthetic data only; identification assumptions are supplied by the fixture design, not inferred from observations. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"z-causal_inference-estimand-target","generated_at":"2026-09-29T14:38:58.793562+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic synthetic study model isolates this data-contract defect; outputs alone establish no real-world causal identification.","root_cause":"A complete synthetic potential-outcome table is averaged across the wrong target population.","sha256":"6d4ae186fc5c08cec51670adb332244d2c7b73a758789819225dc2514352f8e6","title":"An ATT request silently averages untreated potential outcomes · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.711,"exit_code":1,"observations":[{"actual":5.0,"check":"ATT membership","expected":2,"passed":false},{"actual":5.0,"check":"ATE","expected":5,"passed":true},{"actual":1.0,"check":"negative treated","expected":-2,"passed":false},{"actual":1.0,"check":"no treated","expected":null,"passed":false},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":null,"check":"null effect treated","expected":0,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ATT membership\", \"actual\": 5.0, \"expected\": 2, \"passed\": false}, {\"check\": \"ATE\", \"actual\": 5.0, \"expected\": 5, \"passed\": true}, {\"check\": \"negative treated\", \"actual\": 1.0, \"expected\": -2, \"passed\": false}, {\"check\": \"no treated\", \"actual\": 1.0, \"expected\": null, \"passed\": false}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"null effect treated\", \"actual\": null, \"expected\": 0, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.598,"exit_code":1,"observations":[{"actual":5.0,"check":"ATT membership","expected":2,"passed":false},{"actual":5.0,"check":"ATE","expected":5,"passed":true},{"actual":-0.5,"check":"negative treated","expected":-2,"passed":false},{"actual":1.0,"check":"no treated","expected":null,"passed":false},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":0.0,"check":"null effect treated","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ATT membership\", \"actual\": 5.0, \"expected\": 2, \"passed\": false}, {\"check\": \"ATE\", \"actual\": 5.0, \"expected\": 5, \"passed\": true}, {\"check\": \"negative treated\", \"actual\": -0.5, \"expected\": -2, \"passed\": false}, {\"check\": \"no treated\", \"actual\": 1.0, \"expected\": null, \"passed\": false}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"null effect treated\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}