Why "Poverty" Outpredicts Income in Our Proficiency Models

Why "Poverty" Outpredicts Income in Our Proficiency Models
Regenerated: 2026-08-06

Short answer
Both statements can be true at once:
- Income and poverty are strongly related.
- Poverty can still be the better predictor of proficiency.

Plain-language explanation
1) Income and poverty overlap, but they are not the same signal.
- In our school-level data, per-capita income and Students Experiencing Poverty are strongly related, but far from identical.
- Across ELA, Math, and Science, the scored-student-weighted correlation is about -0.66 to -0.67 for per-capita income and -0.62 to -0.65 for median household income.
- Even a correlation of -0.67 implies shared variance of about 45%, leaving substantial non-overlap.

2) The two measures are not equally close to the students being tested.
- Students Experiencing Poverty is a school-population hardship/composition measure.
- ACS per-capita income is a tract-level mean for all residents around a school.
- A measure tied to enrolled students usually tracks school outcomes more directly.

3) Per-capita income is a mean and can be skewed.
- High earners can raise tract mean income even when many enrolled students face hardship.
- That weakens income as a direct proxy for school hardship burden.

4) Poverty captures hardship channels more directly linked to learning disruption.
- ODE's poverty field reflects student hardship categories (for example SNAP/TANF eligibility, foster care, houselessness, migrant status).
- Those conditions can affect attendance continuity, stress load, and day-to-day school access.

5) The model results match this interpretation.
- In ordinary-school five-fold cross-validation tests, all outcomes and weights use students with reported Level 1-4 results:
  - ELA:
    - BA+ + Attendance + Median Household Income: 0.5258
    - BA+ + Attendance + Poverty: 0.6552
    - BA+ + Attendance + Median Household Income + Poverty: 0.6641
  - Math:
    - BA+ + Attendance + Median Household Income: 0.6599
    - BA+ + Attendance + Poverty: 0.6908
    - BA+ + Attendance + Median Household Income + Poverty: 0.6922
  - Science:
    - BA+ + Attendance + Median Household Income: 0.3934
    - BA+ + Attendance + Poverty: 0.5141
    - BA+ + Attendance + Median Household Income + Poverty: 0.5196

The seven eligible ordinary-school observations reported as under 5% poverty use the documented 2.5% interval midpoint; raw disclosures and bounds remain in the processed data.

Interpretation
- Income remains useful as broad community context.
- Poverty appears to carry more independent school-level signal for proficiency.
- Concise framing:
  "Income and poverty both matter, but poverty is a closer measure of student hardship and therefore a stronger predictor in this model framework."
- Plain-language formulation:
  "Per-capita income is a neighborhood-wide average for everyone living in the school's tract, while the poverty measure reflects hardship among students actually enrolled in the school."

Caution
- These are school-level observational associations, not causal proof.