Environmental regulation stringency — emissions caps, standards, phase-out mandates, carbon pricing, renewable portfolio standards.
Product-market regulation, entry barriers, licensing burdens, network-industry regulation, price controls.
CAA Amendments 1990 (Pub. L. 101-549), signed 15 November 1990. Title IV established the Acid Rain Program — the world's first large-scale cap-and-trade regime, targeting SO2 from 263 coal-fired power plants with 10M ton reduction from 1980 levels by 2010; NOx standards for mobile and stationary sources; Title V operating-permit regime; ozone/air-toxics/CFC-phaseout provisions. By 2010 SO2 emissions fell 67% vs 1980 baseline at ~$3B/year compliance cost (vs ex-ante $7.5B/year estimate).
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.