How the blight score works

The platform estimates the net public value of a blight intervention on a specific parcel: direct remediation cost against the value restored to neighboring homes, the taxes and service costs the public recovers, and safety. It follows the public-cost frame the Urban Redevelopment Authority itself commissioned (Center for Community Progress, 2017).

// Net public value (v6.6, September 2026) — OMB A-94 NPV, 20 years, 3.1% real
NPV = − intervention_cost + one_time_benefit + PV(annual_benefits)

intervention_cost  = base_cost[demolition|rehab|land_bank|conservatorship|p3]
                     × FRED cost index (construction PPI, or legal-services CPI)

one_time_benefit   = value restored to RESIDENTIAL neighbors within 500 ft:
                     Σ neighbor_value × 3.15% × min(distressed_structures_nearby, 5) / n
                     (Community Progress for the URA, 2017 — the parcel's OWN value is the
                      owner's, shown separately, never counted as public benefit)

annual_benefits    = tax recovered where tax is actually being lost
                   + service cost the city stops paying at a distressed property
                     (measured: $1,425/yr in 2015 $, rolled to today by CPI-U)
                   + crime reduction (DOJ social cost × Branas attribution)

Every positive figure is Solid: nothing in the NPV rests on a projected or
allocated community benefit. Rankings use urgency first (blight tier, then
whether the public already has authority to act), and net public value as
the tie-breaker; the user may switch the order.

Limitations: The ROI model estimates economic value restoration, not financial return to any single investor. Remediation cost figures are medians calibrated by FRED construction-PPI; actual costs vary by contractor and condition. Adjacent-value restoration applies the Community Progress spillover rate to each parcel's actual residential neighbors within 500 feet — a modeling assumption grounded in published hedonic studies, not a measured outcome on these parcels. TIF amplification assumes the parcel comes back onto tax rolls within 3 years of remediation. The model has not been validated against a held-out sample of known-outcome parcels.

Solid, by construction (v6.6, September 2026): every net-public-value figure counts only recovered taxes, neighbors' property value, avoided service cost and safety. The projected community benefit that earlier versions allocated from Opportunity Atlas tract estimates (2018 release, children born 1978–83) was removed from every figure in September 2026 after it was found to decide the sign of most positive recommendations; the Atlas remains a context layer for the equity check on every ranked list. Every figure also carries a plausible range built from our own cost and assessment reference classes, not a fitted confidence interval. Future benefits are discounted at 3.1% real (OMB Circular A-94) over 20 years. The separate “cost of leaving things as they are” figure is fiscal — tax being lost, measured service cost, and the tax forgone on depressed neighbor value — stated in today's dollars, with the social cost of crime shown beside it and the items it does not count (water and sewer arrears, health) named.

The co-investment trigger model is the platform's thesis about when blight intervention has its highest marginal return: when a qualifying private-permit event creates a time-bounded window for remediating adjacent blighted parcels before the market reprices them. Below is the qualification logic; real-time alerting off live permit ingestion is on the product roadmap but not yet wired end-to-end.

// Qualification logic (applied to a permit feed)
A permit qualifies as a co-investment trigger when ALL are true:
  1. BBI permit value >= $1,000,000
  2. At least one critical- or high-tier parcel within 500m
  3. Permit type in {commercial, residential, mixed-use, institutional}
  4. Corridor is not in "active remediation" lockout

// Recommended budget per qualifying trigger
recommended_co_investment = permit_value × 0.05

// The 5% figure is informed by three reference points (see report):
//   1. Cuyahoga Land Bank 2009–2023 empirical ratio: 5.6–7.5%
//   2. Pittsburgh inventory cost model: ~$34.8M ÷ ~$683M = 5.1%  (platform-derived)
//   3. HUD/PHFA federal program thresholds: 10–50% public match
// These are three anchor points, not three independent confirmations.