Targeted industrial and sectoral subsidies (renewable energy, chip manufacturing, agriculture, green hydrogen, etc).
General government spending as share of GDP, excluding transfers already captured under fiscal.transfer_expansion to avoid double-counting.
Environmental regulation stringency — emissions caps, standards, phase-out mandates, carbon pricing, renewable portfolio standards.
Luxembourg made standard-class public transport free nationwide from 1 March 2020 across trains, trams, and buses, while keeping first-class rail and some cross-border services outside the free-fare rule. The policy shifted operating cost recovery away from passenger fares and toward general public financing, with stated mobility, congestion, and environmental objectives.
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.