Progressivity of the personal income tax schedule, including top marginal rates, bracket spread, and targeted credits (EITC-equivalents).
General government spending as share of GDP, excluding transfers already captured under fiscal.transfer_expansion to avoid double-counting.
A 1.25 percentage point rise in Class 1, 1A, 1B and Class 4 National Insurance Contributions from 6 April 2022, together with a matching 1.25pp dividend tax rise, intended from April 2023 to become a hypothecated 'Health and Social Care Levy' raising ~£12-13bn/year for NHS backlog clearance and a new adult social-care cap (£86,000 lifetime limit on personal care costs). The NI rise took effect 6 April 2022; it was reversed by the Truss/Kwarteng mini-budget 23 September 2022 and the reversal stood under Sunak. Social-care cap was delayed to October 2025 and ultimately abandoned.
Per invariant 3, reforms are scored by what they did on each channel-separated axis, not by the party that enacted them. This fingerprint is how the policy-match engine finds historical analogues.
Explicit links are curated by the author. Inferred links are hypotheses in the library that test the same axes this policy moved — the framework's answer to "what does the data say about a policy like this?".
Ranked by axis-fingerprint overlap with this policy. Direction match bolded — those are the closest historical analogues. Shape of the match is what drives policy-outcome comparison, not the country or party label.