Environmental regulation stringency — emissions caps, standards, phase-out mandates, carbon pricing, renewable portfolio standards.
Progressivity of the personal income tax schedule, including top marginal rates, bracket spread, and targeted credits (EITC-equivalents).
Brennstoffemissionshandelsgesetz (BEHG, 2019) introducing a national emissions trading system for heating and transport fuels outside the EU ETS. Launched 1 January 2021 at €25/t CO2, scheduled to rise to €55/t by 2025 then move to an auction-based corridor (€55-€65/t) in 2026. Revenue used for EEG-Umlage reduction and Klimageld promise (implementation delayed). One of the first national sectoral ETS schemes in Europe.
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.