£35 billion extra: what would it pay for? REPRODUCE THIS INVESTIGATION Repeat the published-number checks, then see exactly where the available data stops. You will need: A browser and Excel, another spreadsheet app, or Python 3 for the optional calculation script ACCESS AND DATA LIMITS These files contain our factual transcription and arithmetic from published rounded inputs. They contain neither the unrounded IFS workbook nor the original IFS chart artwork, private correspondence or individual departmental model. Matching the rounded total is not a full replication. WORKING FILES Source notes: https://tallycat01.com/downloads/35-billion-public-spending-source-notes.txt Timeline: https://tallycat01.com/downloads/35-billion-public-spending-timeline.csv 1. Open the original figure Open the IFS chapter and find Figure 6.11 and its accompanying notes. Confirm that the amounts refer to extra departmental spending in 2030/31. Keep in mind: Use the adjusted figure components, not a sum of all rows in Table 6.2. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 2. Download the working files Download the rounded components CSV and growth-rate CSV below. The files keep the amount, period, units, source and limits beside each input. Our labels explain the source in our own words. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 3. Rebuild the £35 billion total Add the four adjusted components in the components file. The £9bn combines health growth with protecting other departments’ combined buying power. 11 + 9 + 4 + 11 = 35 Keep in mind: The separate Table 6.2 productivity row is £12bn. Figure 6.11 uses £11bn after an overlap adjustment; substituting 12 would produce 36. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 4. Repeat the buying-power examples In the growth file, each scenario starts at 100 in 2027/28. Apply its annual real growth rate three times to reach 2030/31. 100 × (1 + annual rate / 100)^3 Keep in mind: For the second scenario, other departments: 100 × 0.98^3 = 94.1192. These are aggregate buying-power examples, not equal cuts or service-output forecasts. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 5. Keep the starting points separate Each scenario is separately rebased to 100. The slower health scenario also changes earlier spending. Do not compare the resulting indices as equal cash budgets at the endpoint. Keep in mind: Other departments excludes devolved block grants and the Treasury Reserve. Check the Figure 6.10 notes for boundaries. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 6. Repeat the price illustration Use the original expected price factor 1.085 and alternative factor 1.121 from the separate inflation illustration. Divide rather than subtract percentages. 100 × 1.085 / 1.121 = 96.7886 Keep in mind: The approximately 3.2% loss applies to this fixed-cash illustration, not to every department. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures 7. Check definitions and vintages Read Treasury Table 5.6, OBR Chapter 5 and ONS Tables 1 and 3. Keep cash versus inflation-adjusted spending, running costs versus investment, geography and forecast dates separate. Spending Review 2025, Table 5.6: https://www.gov.uk/government/publications/spending-review-2025-document/spending-review-2025-html Economic and fiscal outlook: March 2026: https://assets.publishing.service.gov.uk/media/69a6d7b62e1f4fbda4252208/economic-and-fiscal-outlook-march-2026-web-accessible.pdf Public service productivity, quarterly, UK: January to March 2026: https://www.ons.gov.uk/economy/economicoutputandproductivity/publicservicesproductivity/bulletins/publicserviceproductivityquarterlyuk/januarytomarch2026 8. Run the script and retain the limits The recalculation ZIP contains the same CSV inputs, a plain Python calculation and expected results. Run python calculate.py in its extracted folder, or use the formulas above in Excel. Keep in mind: The IFS workbook has been requested. The next saved availability check is 28 October 2026; no automatic analysis or publication is promised. Public service spending: plans and pressures: https://ifs.org.uk/publications/public-service-spending-plans-and-pressures Budget date confirmation: https://www.gov.uk/government/news/budget-to-move-power-and-money-out-of-westminster-and-into-every-postcode-around-britain ADDITIONAL WORKING FILES Rounded components / CSV: https://tallycat01.com/downloads/35-billion-public-spending-components.csv Buying-power inputs / CSV: https://tallycat01.com/downloads/35-billion-public-spending-growth.csv Calculation method / TXT: https://tallycat01.com/downloads/35-billion-public-spending-method.txt Repeat the calculations / ZIP: https://tallycat01.com/downloads/35-billion-public-spending-recalculate.zip Evidence checked: 12 October 2026 Research and production assisted by AI