Fix MTR calculation to use hbai_household_net_income#64
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nwoodruff-co wants to merge 8 commits intomainfrom
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Fix MTR calculation to use hbai_household_net_income#64nwoodruff-co wants to merge 8 commits intomainfrom
nwoodruff-co wants to merge 8 commits intomainfrom
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- Fix map_transition_to_real_world: use period-0 anchor scale factor so baseline levels carry the full growth path rather than collapsing to a flat constant each period - Add scripts/run_tpi_and_export.py: runs SS+TPI for baseline and a 1pp basic rate reform, exports results to tpi_results.xlsx with optional pre-2026 ONS/OBR historical rows (light yellow) prepended to the baseline sheet - Add scripts/tpi_charts_plotly.py: single-page 2×3 chart showing five variables as % of GDP and GDP in £bn; baseline = OBR Nov 2025 EFO outturn + forecast; reform = OBR baseline × TPI % change from model; dashed reform line only, grey dotted boundary at outturn/forecast split
Extend chart baseline back to 2000-01 by fetching ONS YBHA/NPQS/ABJQ calendar-year series and converting to fiscal years via the existing _fy_from_calendar() helper. OBR table 1.4/1.2 data takes priority from 2008-09 onwards; ONS rows are only prepended for earlier years. Also extend hardcoded _fy_tax_revenue() back to 2000-01 using HMRC outturn data, and update x-axis range to use HIST_START_FY constant.
- Recalibrate adjustment_factor_for_cit_receipts from 0.309 → 1.1785 to match UK CT/GDP ~3.3% (was underestimating at 0.8% using US default) - Add run_ct_and_export.py: SS+TPI for baseline (cit=0.27) and reform (cit=0.28), exports 3-sheet xlsx with historical actuals + model output - Add ct_charts_plotly.py: 6-panel interactive Plotly charts mapping model % changes onto OBR outturn/forecast baseline - Add ct_tpi_results.xlsx and rendered HTML charts - Add ct_reexport.py (interim correction script, now superseded) Dynamic GE estimate: CT +1pp raises ~£2.3-2.6bn/yr tax revenue vs HMRC static RR of £3.6-4.0bn, with ~£2bn/yr investment drag and £0.5-0.8bn GDP cost in OBR window.
Previously, marginal tax rates were computed by comparing total_income - income_tax before and after a £1 perturbation. This missed NI, UC taper, and benefit interactions — all of which affect the true net income change faced by a household. Switch to hbai_household_net_income (the HBAI poverty measure of disposable income), broadcast from household to person level via map_to_entity(..., how="project"). This captures the full tax-benefit wedge including NI, UC, and other means-tested interactions, giving accurate ETR and MTR estimates for the Gouveia-Strauss tax function estimation. Also remove stale dead-code lines (unused BW variable, a redundant frac_payroll assignment, and two inline comments) and fix years[i] formatting in run_oguk.py to handle fiscal-year string labels.
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Changes folded into #63 (obr-grounded-tpi-charts) via cherry-pick. |
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Summary
hbai_household_net_income(projected from household to person level) instead oftotal_income - income_tax. The old approach missed NI, UC taper, and all benefit interactions — systematically understating marginal rates for lower-income households and producing wrong reform ETRs/MTRs.hbai_household_net_incomebefore and after viamap_to_entity(..., how="project"). This captures the full tax-benefit wedge.BWvariable and a redundantfrac_payrollassignment incalibrate(); fixedyears[i]formatting inrun_oguk.pyto handle fiscal-year string labels (e.g."2026-27").Test plan
examples/run_oguk.py ss— verify steady state converges and reform direction is economically sensible (higher IT → lower GDP, not higher)examples/run_oguk.py tpi— verify transition path converges and tax revenue impact is positive