Add contributed EITC match reforms for 9 states without existing state EITC

[DTrim99]

Summary

Adds contributed EITC reforms for states that either:

1. Have income tax but no existing state EITC (9 states) - adds EITC match parameter
2. Have existing nonrefundable EITCs (2 states) - adds option to make refundable

Closes #7894

Part 1: EITC Match Reforms (9 states without state EITC)

States: AL, AR, AZ, GA, ID, KY, MS, ND, WV

These states have income tax but no existing state EITC implementation. The reform adds parameters to create a state EITC as a percentage match of the federal EITC.

Each state includes:

• Parameters (gov/contrib/states/{st}/eitc/):
  • in_effect.yaml - Boolean toggle (default: false)
  • match.yaml - Match rate as fraction of federal EITC (default: 0)
• Reform module (reforms/states/{st}/eitc/)
• Tests (tests/policy/contrib/states/{st}/eitc/)

Usage:

gov.contrib.states.al.eitc.in_effect: true
gov.contrib.states.al.eitc.match: 0.1  # 10% match

Part 2: Refundable EITC Reforms (2 states with nonrefundable EITCs)

States: MO, OH

These states have existing EITCs that are nonrefundable by default. The reform adds a toggle to convert them to refundable credits.

• Missouri (MO): Working Families Tax Credit is nonrefundable starting 2023
• Ohio (OH): EITC is nonrefundable

Each state includes:

• Parameters (gov/contrib/states/{st}/eitc/):
  • in_effect.yaml - Boolean toggle (default: false)
• Reform module that moves EITC from nonrefundable to refundable credits
• Tests

Usage:

gov.contrib.states.mo.eitc.in_effect: true  # Make MO WFTC refundable
gov.contrib.states.oh.eitc.in_effect: true  # Make OH EITC refundable

States NOT included

Already have refundable EITC reforms:

• SC - sc_h3492_eitc_refundable (partial refundability)
• UT - ut_refundable_eitc (age-based refundability)

States with no income tax (no EITC needed):
AK, FL, NV, NH, SD, TN, TX, WA, WY

States with existing state EITC implementations:
CA, CO, CT, DC, DE, HI, IA, IL, IN, KS, LA, MA, MD, ME, MI, MN, MO, MT, NC, NE, NJ, NM, NY, OH, OK, OR, PA, RI, SC, UT, VA, VT, WA, WI

Test plan

• Verify each new state EITC is 0 when in_effect: false
• Verify EITC match states: EITC equals federal EITC × match rate when enabled
• Verify MO/OH: EITC moves from nonrefundable to refundable when enabled

🤖 Generated with Claude Code

[DTrim99]

Program Review: PR #7895 - State EITC Match Reforms

Overview

• Type: Contributed reform (child poverty impact dashboard)
• States: AL, AR, AZ, GA, ID, KY, MO, MS, ND, OH, UT, WV (12 states)
• Reform Types:
  • EITC Match (9 states): AL, AR, AZ, GA, ID, KY, MS, ND, WV
  • Refundable EITC Toggle (2 states): MO, OH
  • Fully Refundable EITC (1 state): UT
• CI Status: All checks passing
• Files Changed: 49 total (12 parameter files, 14 reform Python files, 12 test files, changelog, reforms.py updates)

---

Critical (Must Fix)

1. ND Reference Field Missing Commas - policyengine_us/reforms/states/nd/eitc/nd_eitc_reform.py

Lines 25-30: Python string concatenation bug will merge multiple URLs into one invalid URL.

Current:

reference = (
    "https://www.tax.nd.gov/sites/www/files/documents/forms/individual/2021-iit/form-nd-1-2021.pdf"
    "https://www.tax.nd.gov/sites/www/files/documents/forms/individual/2021-iit/individual-income-tax-booklet-2021.pdf"
    ...
)

Fix Required:

reference = (
    "https://www.tax.nd.gov/sites/www/files/documents/forms/individual/2021-iit/form-nd-1-2021.pdf",
    "https://www.tax.nd.gov/sites/www/files/documents/forms/individual/2021-iit/individual-income-tax-booklet-2021.pdf",
    ...
)

This is a syntax/logic error that will cause invalid data at runtime.

---

Should Address

1. OH Reform Uses Hardcoded Credit List with try/except - policyengine_us/reforms/states/oh/eitc/oh_refundable_eitc_reform.py

Lines 64-79: Hardcoded credit list with silent exception handling is fragile and inconsistent with baseline parameter-driven approach.

for credit in [
    "oh_adoption_credit",
    "oh_cdcc",
    ...
]:
    try:
        other_credits = other_credits + tax_unit(credit, period)
    except Exception:
        pass

Issues:

• oh_adoption_credit was removed in 2023 but code still tries to access it
• Silent failures mask real errors
• Will break if Ohio adds/removes credits

Recommendation: Use parameter-driven approach like baseline adds pattern.

---

2. UT Reform Uses Hardcoded Credit List - policyengine_us/reforms/states/ut/child_poverty_eitc/ut_fully_refundable_eitc_reform.py

Lines 91-107: Hardcoded credit enumeration in ut_non_refundable_credits formula.

Issue: Will break if Utah adds new credits to baseline.

Recommendation: Use parameter-driven approach to match baseline.

---

3. Missing Reference Metadata in Parameter Files - All 20 parameter files

Files affected:

• policyengine_us/parameters/gov/contrib/states/*/child_poverty_impact_dashboard/eitc/in_effect.yaml
• policyengine_us/parameters/gov/contrib/states/*/child_poverty_impact_dashboard/eitc/match.yaml

For contributed reforms, references are not strictly required, but adding a reference indicating these are hypothetical reforms improves clarity:

metadata:
  reference:
    - title: Child Poverty Impact Dashboard Hypothetical Reform
      href: https://policyengine.org/us/research

---

4. Missing Edge Case Tests - Zero Federal EITC - All 12 test files

No tests verify behavior when eitc: 0. This is important to ensure formulas handle zero inputs correctly.

Recommended test:

- name: AL EITC with zero federal EITC
  period: 2024
  reforms: policyengine_us.reforms.states.al.eitc.al_eitc
  input:
    gov.contrib.states.al.child_poverty_impact_dashboard.eitc.match: 0.2
    state_code: AL
    eitc: 0
  output:
    al_eitc: 0

---

5. Missing Edge Case Tests - Wrong State Code - All 12 test files

No tests verify that defined_for state restriction works correctly.

Recommended test:

- name: AL EITC not applied in other state
  period: 2024
  reforms: policyengine_us.reforms.states.al.eitc.al_eitc
  input:
    gov.contrib.states.al.child_poverty_impact_dashboard.eitc.match: 0.2
    state_code: TX
    eitc: 1_000
  output:
    al_eitc: 0

---

6. Missing Refundable Credits Output Tests - AR, AZ, ID, WV test files

These states test xx_eitc but not xx_refundable_credits aggregation.

Files:

• policyengine_us/tests/policy/contrib/states/ar/child_poverty_impact_dashboard/eitc/*.yaml
• policyengine_us/tests/policy/contrib/states/az/child_poverty_impact_dashboard/eitc/*.yaml
• policyengine_us/tests/policy/contrib/states/id/child_poverty_impact_dashboard/eitc/*.yaml
• policyengine_us/tests/policy/contrib/states/wv/child_poverty_impact_dashboard/eitc/*.yaml

---

7. MO/OH Integration Tests Missing - MO and OH test files

Tests don't verify that non-refundable credits aggregation works correctly after reform.

---

---

Suggestions

1. Add Comments for States Without Baseline Refundable Credits

States AL, GA, KY, MS currently have no baseline refundable credits. Add documentation:

# NOTE: AL currently has no baseline refundable credits.
# If AL adds refundable credits in baseline, this formula must be updated.

---

2. Consider Using adds Attribute Pattern

For AR, AZ, ID, WV reforms that use add() + manual + pattern, consider using the adds class attribute for cleaner aggregation.

---

3. Improve Parameter Descriptions

Current descriptions like "Alabama applies a state EITC as a match of the federal EITC" could be more precise:

description: Alabama provides this share of the federal Earned Income Tax Credit under a proposed state Earned Income Tax Credit program.

---

4. Improve Label Formatting

Current: label: Alabama EITC match rate
Better: label: Alabama state EITC match rate

---

5. Add 100% Match Rate Tests

Add tests for match: 1.0 to verify full federal EITC pass-through works correctly.

---

6. Document NC EITC in_effect Pattern Change

The NC reform was simplified to remove the in_effect check from the formula. This is correct (reform activation now happens at load time), but the pattern change should be documented.

---

Validation Summary

Check	Result
Code Patterns	1 critical (ND commas), 2 should-address (hardcoded lists)
Test Coverage	4 gaps (edge cases, integration)
Parameter Metadata	Reference fields missing (should-address for contrib)
CI Status	Passing

---

Review Severity: COMMENT

Rationale:

• The ND missing commas issue is a real bug that should be fixed, but it only affects the reference metadata tuple (not runtime behavior)
• The hardcoded credit lists in OH/UT are maintenance concerns but don't break current functionality
• All CI checks are passing
• This is a contributed reform with relaxed standards

For a contributed reform PR with passing CI, COMMENT is appropriate to flag the issues without blocking merge.

---

Next Steps

To auto-fix issues: /fix-pr 7895

Priority Fixes:

1. Add commas to ND reference tuple (Critical)
2. Add zero EITC edge case tests (Should Address)
3. Add wrong state code tests (Should Address)

Optional Improvements:
4. Refactor OH/UT to use parameter-driven credit aggregation
5. Add reference metadata to parameter files
6. Add integration tests for MO/OH refundable credit flows