Correct uprating claims on the SPM poverty methodology page

changelog.d/spm-poverty-uprating-claims.fixed.md

@@ -0,0 +1 @@
+Correct the uprating description on the SPM poverty methodology page so it matches the code: rent follows the default CBO adjusted gross income projection, not CPI-U.

docs-quarto/methodology/spm-poverty.qmd

@@ -50,7 +50,7 @@ The [MOOP decomposition page](moop-decomposition.qmd) records the design and the
 
 Population results use the Microcosm US dataset. The current default is Build P: 57,240 Current Population Survey Annual Social and Economic Supplement households with 166,321 people, whose weights are fitted to 5,659 administrative and demographic targets (IRS Statistics of Income by state and by income, Census population estimates by age, sex and state, CMS Medicaid and Marketplace enrollment, USDA SNAP participation and benefits, SSA SSI, TANF, state tax collections and BEA national accounts). Poverty rates are never a target. That is a rule of the calibration, not an accident: a model whose weights were fitted to survey-based poverty rates could not be checked against them.
 
-2025 values are the 2024 survey values carried forward by the model's uprating parameters: CBO's projections of adjusted gross income by source for most income variables, IRS Statistics of Income series for others, CPI-U for rents, CMS per-capita spending for medical expenses, and Census population estimates for the weights. Household composition is held at its 2024 state. The population is projected, not resampled.
+2025 values are the 2024 survey values carried forward by the model's uprating parameters: each uprated input grows by the ratio of its uprating parameter between the two years. The main income sources (employment, self-employment and partnership income, Social Security, pensions and retirement account distributions, capital gains, dividends, interest, rental and farm income, and unemployment compensation) follow [IRS Statistics of Income series](https://github.com/PolicyEngine/policyengine-us/tree/main/policyengine_us/parameters/calibration/gov/irs/soi). Each series holds IRS totals through its last recorded year and a CBO projection extends it from there, so the growth applied from 2024 to 2025 is CBO's. Non-premium medical spending and the survey-reported premiums that enter SPM resources follow [CMS's projection of per-capita out-of-pocket health spending](https://github.com/PolicyEngine/policyengine-us/blob/main/policyengine_us/parameters/calibration/gov/hhs/cms/moop_per_capita.yaml). Child support paid and received, the energy subsidy, real estate taxes and household assets follow [CPI-U](https://github.com/PolicyEngine/policyengine-us/blob/main/policyengine_us/parameters/gov/bls/cpi/cpi_u.yaml). Every other dollar input, including rent and child care expenses, follows [CBO's projection of total adjusted gross income](https://github.com/PolicyEngine/policyengine-us/blob/main/policyengine_us/parameters/calibration/gov/cbo/income_by_source.yaml), the default that [`default_uprating.py`](https://github.com/PolicyEngine/policyengine-us/blob/main/policyengine_us/tools/default_uprating.py) assigns. Household weights follow the model's [total population series](https://github.com/PolicyEngine/policyengine-us/blob/main/policyengine_us/parameters/calibration/gov/census/populations/total.yaml), which takes its values from CBO's demographic outlook; person and SPM unit weights read the household weight. Inputs without an uprating parameter (ages, take-up indicators, tenure, geography) carry over unchanged, so household composition is held at its 2024 state. The population is projected, not resampled.
 
 ## What the model does not do