{"model_version":"p5v5-2026.07","serving_model_version":"p5v5-2026.07","as_of":"2026-07-13","historical_backtest_v0":{"scope":"arms-length 2-4 unit resales, Logan Square/Avondale 2022-24, leave-one-out (OLD mixed-condition engine, retired baseline)","mdape_pct":20.1,"mape_pct":33.4,"within_10_pct":28,"within_20_pct":50,"bias_pct":4.7,"note":"Retired baseline; never presented as current-model accuracy."},"deals_graded":0,"last_data_run":{"kind":"digest-weekly","finished":"2026-09-06T14:00:28.082Z","found":126,"new_count":0},"segments":{"south_side_sfh":{"label":"South Side SFH","n":72,"n_attempted":198,"mdape":15.5,"mape":35.5,"bias_pct":0.7,"w10_pct":32,"w20_pct":62,"suppression_rate":0.636,"n_tier1":72,"n_tier2":0,"luxury_flagged":10,"conf_calibration":{"high_bucket_mdape":14.4,"low_bucket_mdape":10.5,"high_bucket_n":40,"low_bucket_n":4},"note":"Woodlawn/Park Manor/Grand Crossing — the cold deep-value regime the audit flagged (~26% cold undershoot on the old engine)."},"north_side_2_4":{"label":"North Side 2-4 unit","n":38,"n_attempted":180,"mdape":16.4,"mape":19.5,"bias_pct":0.5,"w10_pct":26,"w20_pct":55,"suppression_rate":0.789,"n_tier1":38,"n_tier2":0,"luxury_flagged":52,"conf_calibration":{"high_bucket_mdape":12.7,"low_bucket_mdape":14.6,"high_bucket_n":3,"low_bucket_n":8},"note":"Logan Square/Avondale 2-4 flats (reuses the committed Phase-2 backtest corpus)."},"cook_suburbs":{"label":"Suburban Cook SFH (Oak Park/Berwyn)","n":104,"n_attempted":243,"mdape":12.2,"mape":20.4,"bias_pct":3.8,"w10_pct":41,"w20_pct":72,"suppression_rate":0.572,"n_tier1":104,"n_tier2":0,"luxury_flagged":66,"conf_calibration":{"high_bucket_mdape":11.3,"low_bucket_mdape":11.3,"high_bucket_n":43,"low_bucket_n":5},"note":"Oak Park / Berwyn SFH slice — suburban Cook parity check."},"million_plus":{"label":"$1M+ luxury (Tier-1 only)","n":162,"n_attempted":278,"mdape":13.8,"mape":31.6,"bias_pct":0.5,"w10_pct":42,"w20_pct":64,"suppression_rate":0.417,"n_tier1":162,"n_tier2":0,"luxury_flagged":278,"conf_calibration":{"high_bucket_mdape":10.7,"low_bucket_mdape":36.3,"high_bucket_n":75,"low_bucket_n":5},"note":"Lincoln Park/Lakeview SFH, holdout sale >= $1M. Luxury Tier-1-only rule FORCED; sale price never feeds ARV."},"lake_county":{"label":"Lake County (expected suppression)","n":0,"n_attempted":5,"mdape":null,"mape":null,"bias_pct":null,"w10_pct":null,"w20_pct":null,"suppression_rate":1,"n_tier1":0,"n_tier2":0,"luxury_flagged":0,"conf_calibration":{"high_bucket_mdape":null,"low_bucket_mdape":null,"high_bucket_n":0,"low_bucket_n":0},"note":"Engine is Cook-only for sales; Lake tracts are not ingested. Suppression is the CORRECT behavior — reported honestly. Probed 5 Lake points (incl. golden tract 17097864308); all suppressed."}},"segments_api":[{"id":"south_side_sfh","label":"South Side SFH","n":72,"mdape_pct":15.5,"ppe20_pct":62,"bias_pct":0.7,"suppression_rate":0.636,"as_of":"2026-07-13"},{"id":"north_side_2_4","label":"North Side 2-4 unit","n":38,"mdape_pct":16.4,"ppe20_pct":55,"bias_pct":0.5,"suppression_rate":0.789,"as_of":"2026-07-13"},{"id":"cook_suburbs","label":"Suburban Cook SFH (Oak Park/Berwyn)","n":104,"mdape_pct":12.2,"ppe20_pct":72,"bias_pct":3.8,"suppression_rate":0.572,"as_of":"2026-07-13"},{"id":"million_plus","label":"$1M+ luxury (Tier-1 only)","n":162,"mdape_pct":13.8,"ppe20_pct":64,"bias_pct":0.5,"suppression_rate":0.417,"as_of":"2026-07-13"},{"id":"lake_county","label":"Lake County (expected suppression)","n":0,"mdape_pct":null,"ppe20_pct":null,"bias_pct":null,"suppression_rate":1,"as_of":"2026-07-13"}],"premium_model":{"status":"v3_serve_equivalent_yardstick_closed_undershoot","version":"premiums.v4-2026.07","county_prior":1.2737,"county_prior_by_type":{"sfh":1.3128,"mf2_4":1.2713},"n_pairs_by_type":{"sfh":6144,"mf2_4":690,"other":1229},"denominator_mix":{"obs":{"serve_nbhd":7827,"serve_zip":214,"broad":22},"areas":{"serve_equiv":672,"mixed":18,"broad":1}},"clamp":{"lo":0.9,"hi":3.5,"n_clamped_lo":1098,"n_clamped_hi":35,"n_clamped":1133,"n_dropped_sanity":10},"prior_v2":{"county_prior":1.3067,"county_prior_by_type":{"sfh":1.3316,"mf2_4":1.6287}},"result":{"south_side_sfh":{"mdape":"42.4->15.5","bias_pct":"-31.3->0.7","gate":"|bias|<=12 AND MdAPE<=25","gate_met":true},"north_side_2_4":{"mdape":"19.7->16.4","bias_pct":"+9.2->0.5"},"cook_suburbs":{"mdape":"13.9->12.2","bias_pct":"+2.1->3.8"}},"finding":"v3 aligns the premium YARDSTICK with the serve base. The Tier-2 engine multiplies area_median = median of SAME-property-type, arms-length, radius-local sales indexed to the valuation date; v1/v2 divided the renovated resale by a NON-commensurate broad assessor-nbhd, mixed-class, concurrent-year median, so the premium came out ~1.1-1.3 for any key and Tier-2 structurally undershot deep-value SFH. v3 rebuilds the flip-pair denominator to the serve-equivalent base: median same-ptype arms sales in the resale's nbhd (modal-zip fallback), +/-12mo around the resale, indexed to the resale year via the zip curve, excluding own legs + known renovated resale legs (as-is de-contamination). premium = resale / that base; both legs sit at the resale date so the ratio is scale-free and reconstructs the renovated value when applied to the today-indexed serve base. Lookup/schema/shrinkage UNCHANGED -- only the yardstick moved. Result: south_side_sfh bias -31.3% -> 0.7% and MdAPE 42.4 -> 15.5 (success gate |bias|<=12 AND MdAPE<=25 MET); north_side_2_4 MdAPE 19.7 -> 16.4 (bias +9.2 -> 0.5) and cook_suburbs MdAPE 13.9 -> 12.2 (bias +2.1 -> 3.8) BOTH IMPROVED (no degradation). The county mf2_4 prior falls 1.6287 -> 1.2713 (the same-ptype base is higher than the old SFH-diluted mixed median); the county SFH prior is ~unchanged (1.3316 -> 1.3128) because bifurcation is concentrated in deep-value AREAS, not the county mean -- the fix is area-specific (e.g. nbhd 70030 SFH 1.13 -> ~1.97), exactly as the yardstick diagnosis predicted. The premium build never reads the backtest holdout (no overfitting)."},"rehab_calibration":{"status":"v1_rough","label":"v1 ROUGH — implied-rehab identity is noisy (unobserved buy discount, hold, margin, financing). Directional bias check on base $/sf, not a point estimate.","method":"implied_rehab = (resale-buy) - 15%*resale - holding(0.85*buy*10.5%*mo/12) - 8%*resale - 2%*buy; engine = GLA×base_psf(scope)×(1+Σλ)","bases_psf":{"cosmetic":38,"moderate":80,"gut":135,"structural":200},"target_margin":0.15,"corpus":["sc_south_side_sfh.json","sc_cook_suburbs.json","sc_million_plus.json","bt_logan.json","bt_south.json"],"overall":{"n_pairs":708,"mape_pct":55.9,"bias_pct":-40.1},"by_area":{"27020":{"n":7,"mape_pct":66.6,"bias_pct":-60.5},"27030":{"n":10,"mape_pct":65.9,"bias_pct":-52.1},"27050":{"n":9,"mape_pct":50.7,"bias_pct":-40.1},"27060":{"n":9,"mape_pct":61.7,"bias_pct":-36.6},"27080":{"n":12,"mape_pct":43.3,"bias_pct":-24.5},"27090":{"n":6,"mape_pct":71.2,"bias_pct":-22.4},"27100":{"n":7,"mape_pct":55.2,"bias_pct":-22.5},"31091":{"n":5,"mape_pct":34.3,"bias_pct":-17.8},"31092":{"n":3,"mape_pct":74.1,"bias_pct":-74.1},"70010":{"n":27,"mape_pct":54.8,"bias_pct":-30.1},"70020":{"n":4,"mape_pct":106.7,"bias_pct":94.1},"70030":{"n":297,"mape_pct":46.1,"bias_pct":-33.1},"70070":{"n":61,"mape_pct":53.1,"bias_pct":-22.8},"70080":{"n":10,"mape_pct":45,"bias_pct":-34.5},"70111":{"n":23,"mape_pct":55.5,"bias_pct":-47.8},"71070":{"n":47,"mape_pct":56.3,"bias_pct":-23.2},"71082":{"n":4,"mape_pct":41.2,"bias_pct":-20.5},"71180":{"n":12,"mape_pct":37.1,"bias_pct":-23.2},"72092":{"n":11,"mape_pct":48,"bias_pct":-2.6},"72170":{"n":11,"mape_pct":62,"bias_pct":59.2},"72260":{"n":15,"mape_pct":55.3,"bias_pct":-55.3},"73084":{"n":11,"mape_pct":84.8,"bias_pct":-84.8},"73093":{"n":15,"mape_pct":88.3,"bias_pct":-88.3},"73120":{"n":7,"mape_pct":85.6,"bias_pct":-85.6},"73150":{"n":10,"mape_pct":88.3,"bias_pct":-88.3},"74011":{"n":7,"mape_pct":86.5,"bias_pct":-86.5},"74012":{"n":43,"mape_pct":88.3,"bias_pct":-85.5},"77150":{"n":7,"mape_pct":73.6,"bias_pct":73.6}},"caveat":"Permit-linked reported_cost (stronger signal) not yet joined; hold months approximated from sale-year granularity in the cache. Treat MAPE as directional."},"segments_as_of":"2026-07-13","artifact_model_version":"p5v5-2026.07","flip_pair_validation":{"n_graded":248,"mdape_pct":21,"bias_pct":-14.3,"as_of":"2026-07-10","model_version":"p2v1-2026.07"},"model_versions":{"model":"p5v5-2026.07","underwrite":"p5v5-2026.07","serving":"p5s12-2026.07"},"warnings":["flip_pair_artifact_stale"]}