Direction of monetary-base expansion decisions relative to trend. Separate from fiscal.transfer_expansion even when correlated.
Bank of Japan Policy Board introduced the Zero Interest Rate Policy (ZIRP) on 12 February 1999, reducing the uncollateralised overnight call rate target to "as low as possible" (effectively 0.03%, then 0.02%). Accompanied by guidance commitment to maintain policy "until deflationary concerns subside" — pioneering global example of explicit forward guidance. Lifted 11 August 2000 against government objection in a 7-2 Policy Board vote, widely criticised ex post as premature given the subsequent dot-com-era downturn; reinstated in modified form alongside Quantitative Easing from 19 March 2001.
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.