Sources and Methods Verification Report
This page shows where the numbers came from, how they were calculated, and how they were checked. It summarizes source classes, model assumptions, calculated values, and audit findings for the Contra Costa Plan B report.
Verification and Updates
This work is split into two explicit phases: first verification with recommendations, then implementation of fixes and updates.
Phase 1: Verification completed with recommendations
Phase 2: Fixes and updates applied
Scope: Contra Costa Plan B report
Jargon and readability check: Pass
Missing citations in audited set: 0
Verification Categories
Each category below is evaluated separately so readers can see exactly what was checked and how it passed.
| Category | Definition | Status | Coverage |
|---|---|---|---|
| Direct Source Values | Values stated explicitly in cited primary sources with no transformation. | Pass | 12 values classified as direct source values. |
| Source-Derived (Interpreted) Values | Values interpreted from source language or context with an explicit interpretation rule. | Pass | 3 values classified as source-derived values. |
| Assumption and Scenario Parameters | Planning parameters selected for scenario modeling, not directly quoted from source documents. | Pass | 11 assumptions tracked and labeled. |
| Calculated Estimations | Values computed from source and interpreted inputs using explicit formulas. | Pass | 9 calculated values validated. |
| Copy-Language Accuracy | Public wording separates sourced facts from modeled outputs and avoids overstated claims. | Pass | Source-versus-model wording corrected in public copy. |
| Citation Traceability | Each audited public claim maps to a source citation, file path, or formula record. | Pass | Missing citations in audited set: 0. |
| Jargon and Readability | Public-facing language uses plain wording, limits jargon, and stays broadly readable. | Pass | Plain-language clarity check completed and documented. |
Direct Source Values
| Value | Number | Source |
|---|---|---|
| Measure B annual revenue estimate | $150M | Official Measure Wording List (ballot text) |
| FY26-27 position-cost increase | $208M | FY26-27 Budget Development Key Considerations, p. 13 |
| FY24-25 unassigned General Fund reserve | $584.6M | FY26-27 Budget Development Key Considerations, p. 8 |
| FY24-25 reserve shares of revenues | 23.8% unassigned / 49.4% total | FY26-27 Budget Development Key Considerations, p. 8 |
| General Fund reserve policy minimums | 5% unassigned / 10% total | General Fund Reserve Policy (2011) |
| FY24-25 General Fund balance mix | $19.8M / $4.3M / $1.1M / $604M / $584.6M | ACFR 2025 General Fund balance categories |
Source-Derived (Interpreted) Values
| Value | Number | Source |
|---|---|---|
| FY26-27 baseline gap | $23M | Budget Development Key Considerations, pp. 10-11 |
| Cumulative health shortfall anchor | $239M | Resolution 2026-40, Recital H |
| Reserve policy floor proxy used in model | $123M | Reserve Policy plus FY26-27 revenue context |
Key Assumptions
These assumptions are the policy and scenario choices used to turn source inputs into the public model shown elsewhere on the site.
| Assumption | Value | Why it is used |
|---|---|---|
| Health shortfall annual growth factor | 1.5 | Creates the exponential annual path that sums to the $239M cumulative anchor by FY28-29. |
| Annual pay and benefits growth rate | 5% | Extends the FY26-27 $208M pressure point into later years of the scenario. |
| Reserve bridge shares by year | 60%, 33%, 18%, 0% | Shows reserves as a declining temporary bridge instead of a permanent solution. |
| Revenue increase shares by year | 15%, 18%, 22%, 26% | Shows a phased increase in other revenues across the four-year scenario. |
| FY26-27 spending-cut split | 70% service adjustments / 30% operations | Keeps the donut chart aligned with the main model while preserving the displayed illustrative split. |
Calculated Estimations
These values are not quoted directly from a source document. They are computed from the source values and assumptions listed on this page.
| Metric | Value | Formula |
|---|---|---|
| FY26-27 health shortfall | $50M | round(239/(1+1.5+1.5^2)) |
| FY27-28 health shortfall | $75M | round(FY26-27 * 1.5) |
| FY28-29 health shortfall | $114M | 239 - FY26-27 - FY27-28 |
| FY29-30 health shortfall | $171M | round(FY28-29 * 1.5) |
| FY26-27 total pressure | $281M | 23 + 208 + 50 |
| FY26-27 gap after Measure B | $131M | 281 - 150 |
| Measure B coverage share | 53% | round((150/281)*100) |
| Unassigned reserve above policy minimum | $462M | round(584.6 - 123) |
| Current reserve multiple of minimum | 4.8x | round(584.6 / 123, 1) |
Audit Findings
F-001 (Medium)
Resolved 2026-03-25Verification recommendation: Clarify wording so model-derived values are not presented as direct source quotes.
Fix/update applied: Public wording now explicitly distinguishes model outputs from direct source values.
F-002 (Medium)
Resolved 2026-03-25Verification recommendation: Add a clear method note for the reserve floor proxy so interpretation is transparent.
Fix/update applied: Reserve floor proxy language now includes an explicit methodology note in public copy.
F-003 (Low)
Resolved 2026-03-25Verification recommendation: Align health shortfall path displays across public site views.
Fix/update applied: Public health shortfall path displays are now aligned across site views.
F-004 (Low)
Resolved 2026-03-25Verification recommendation: Reduce jargon and keep public-facing wording broadly readable and easy to scan.
Fix/update applied: Plain-language edits were applied to public copy so source claims, model outputs, and caveats are easier to understand.