About & Methodology
Transparency in data sources, scoring methods, and analytical assumptions.
Mission
ImpactLink is a GIS-based analytics platform that reveals where need concentrates in Philadelphia. By layering census, food access, and health data at the tract level, it identifies neighborhoods where multiple risk factors converge -- creating a shared evidence base for nonprofits, funders, government agencies, and community organizations working to reduce poverty and improve outcomes.
All data is publicly sourced from federal agencies. No personally identifiable information is collected, stored, or displayed. The platform operates on aggregate census tract statistics only.
Data Sources
US Census ACS 2022
B25070Gross rent as a percentage of household income. Tracts where 30%+ of renters pay more than 30% of income toward rent are flagged for housing stress.
US Census ACS 2022
B17001Poverty status in the past 12 months by sex and age. Tracts with 30%+ poverty rate are flagged for high poverty concentration.
USDA Food Access Research Atlas
LILALow-Income, Low-Access (LILA) tract designation. Identifies food deserts where residents live more than 0.5 miles from the nearest supermarket in an urban area.
CDC PLACES 2024
DIABETESModel-based estimates of diabetes prevalence at the census tract level. Tracts at or above the 75th percentile of diabetes prevalence are flagged for chronic health burden.
HRSA / PA WIC / Philadelphia Works
Provider locations for Federally Qualified Health Centers (FQHCs), WIC offices, food pantries, shelters, behavioral health clinics, and workforce development centers. Geocoded and verified against official directories.
Risk Flag Methodology
Each census tract is evaluated against four binary risk indicators. A tract with 2 or more active flags is classified as a hotspot.
Housing Stress
Rent burden >= 30% of household income (Census ACS B25070)
High Poverty
Poverty rate >= 30% (Census ACS B17001)
Low Food Access
USDA LILA flag = true (>0.5 mi to supermarket, low-income)
Chronic Health Burden (Diabetes)
Diabetes prevalence > 75th percentile (CDC PLACES 2024)
Hotspot threshold: Need >= 2 active flags. Tracts with 3-4 flags represent the highest concentration of overlapping risk.
Gap Score Formula
Gap Score = Need Flags × (1 / (1 + Provider Count))
The gap score combines the number of active risk flags with the inverse of provider density. A tract with many needs and few providers scores higher, indicating greater urgency for intervention.
Examples
Provider Verification
92 provider locations geocoded via the Census Bureau Geocoder API and verified against public directories. Each location is mapped to its containing census tract.
ROI Calculator Benchmarks
The ROI calculator uses per-service cost and downstream savings estimates drawn from published research. These are indicative benchmarks, not precise figures -- actual costs vary by organization and program design.
| Source | Used For |
|---|---|
| SAMHSA | Behavioral health program cost estimates and service duplication rates |
| CDC | Chronic disease management cost benchmarks and prevention savings |
| HRSA | FQHC service delivery costs and capacity metrics |
| HUD | Housing stability program costs and shelter diversion savings |
| Urban Institute | Service duplication estimates and coordination effectiveness factors |
Data Currency
Data as of March 2026. The automated pipeline refreshes weekly from federal sources (US Census, USDA, CDC PLACES) every Sunday at midnight UTC via AWS EventBridge. Provider locations are verified against public directories on a quarterly basis.