IESET.
Policies·jp_boj_bubble_easing_tightening_1987_1991

BoJ bubble-era easing and abrupt tightening 1987-1991

JPN·1987 – 1991·LDP governments; BoJ Governors Sumita then Mienocandidate
movesmonetary expansion direction↑central bank independence↓

What the policy did

Bank of Japan cut the official discount rate to a post-war low of 2.5% Feb 1987 and held it there through May 1989, partly under Plaza- Accord pressure to support US rebalancing; Governor Mieno tightening from Dec 1989 raised rates to 6.0% by Aug 1990. The sustained easing fed Nikkei 225 to 38,915 peak Dec 1989 and land-price bubble; subsequent tightening punctured asset markets, triggering three- decades deflation-adjacent stagnation.

Policy-content fingerprint — what this policy moved, on which axes

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.

intended
↑
monetary expansion direction
monetary.monetary_expansion_direction
Direction of monetary-base expansion decisions relative to trend. Separate from fiscal.transfer_expansion even when correlated.
increased · strong
expansionary (balance sheet, rates lower than Taylor)
Sustained easing 1987-1989 at 2.5% ODR.
unintended / side-effect
↓
central bank independence
monetary.central_bank_independence
De jure and de facto independence of the central bank from fiscal authority. Per D.1.5 scope, one of the framework's defensible monetary positions.
decreased · moderate · unintended
lower independence (fiscal dominance, politicised appointments)
BoJ operated under MoF subordination until 1998 Bank of Japan Act.

Enacted by

Empirical evidence — linked hypotheses

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?".

Truss 2022 mini-budget shows that unfunded fiscal expansion above the ZLB triggers sharp bond-market and currency responses through expected-inflation and risk-premium channels.
unfunded_fiscal_expansion_above_zlb_bond_market_responseinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
SUPPORTED — GBP/USD trough on 2022-09-26 (1.0703) was 5.02% below the 2022-09-22 pre-announcement close (1.1269); log-decline +0.0515 clears the 3.0% threshold …
supported
Across the 2008-2014 ZLB era and the 2020-2021 pandemic-response window, large-scale de-facto monetary finance of fiscal expansion in the US, Japan, and the Eurozone did not produce headline-CPI inflation consistent with naive quantity-theoretic monetisation predictions: cumulative central-bank balance-sheet expansion exceeded 15% of GDP while CPI YoY remained below 3% in each economy across both windows.
monetary_finance_zlb_no_inflationinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
REFUTED — CPI threshold breach: USA zlb_2008_2014 peak 3.81% in 2008; USA covid_2020_2021 peak 4.68% in 2021; Eurozone CPI not loaded
refuted
Every documented modern hyperinflation episode (Cagan ≥50% monthly inflation, Hanke-Krus catalogue) since 1900 falls into one of two categories: (a) the issuing state had material foreign-currency or gold-clause obligations, hard-currency-pegged debt, or external market dependency that left it operating effectively as a currency-user (Weimar reparations, Hungary 1945-46 occupation obligations, Yugoslavia FX debt, Zimbabwe USD obligations 2007+, Venezuela USD oil revenue dependency, Argentina USD debt, Lebanon USD-pegged banking system, Turkey 2021-2024 FX-denominated debt), or (b) the issuing state experienced a documented physical supply collapse independent of the monetary regime (Weimar Ruhr occupation, Hungary post-WW2 occupation/reparation, Zimbabwe land-reform output collapse, Venezuela oil-sector collapse).
currency_user_vs_issuer_hyperinflation_classificationinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
INCONCLUSIVE_DATA_PENDING
run pending
Post-2008 large-scale asset purchase programmes by the Federal Reserve, ECB, Bank of England, and Bank of Japan produced a measurable divergence between asset-price inflation (equities and residential real estate) and headline consumer-price inflation until roughly 2021.
qe_asset_inflation_vs_cpi_divergence_post_2008inferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
refuted — Only 2 of 8 countries had even a 0.10 log-point asset-vs-CPI gap by 2020 (mean GAP_2020 = -0.02). The post-2008 divergence story does not survive a pa…
refuted
Argentina has experienced 12 distinct episodes of annual inflation exceeding 50% since 1945, each preceded by a fiscal deficit exceeding 4% of GDP financed via central bank money creation.
argentina_peronism_recurring_fiscal_inflation_cycle_1945_2023inferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
PARTIAL — cointegration rank=1, α_infl=-0.003073235091341579; episode precedence 2/5 below 8/12 threshold.
partial
In a panel of advanced economies 1987-2007, base-money expansion and broad money growth correlate positively with asset-price indices (equity, real estate) but only weakly with headline CPI inflation.
austrian_monetary_expansion_asset_bubble_not_cpi_panelinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
INCONCLUSIVE_DATA_PENDING — insufficient observations after listwise deletion (21)
run pending
Over 50+ year horizons since the 1971 collapse of Bretton Woods, major fiat currencies (USD, GBP, EUR legacy components, JPY, AUD) have lost substantial purchasing power against hard assets (gold, broad commodity baskets, residential real estate).
fiat_expansion_erodes_currency_purchasing_power_long_runinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
SUPPORTED — 7/7 fiat currencies lost purchasing power against at least one hard-asset benchmark
supported
Every documented hyperinflation episode since 1900 (Weimar Germany, post-WW2 Hungary, Yugoslavia 1990s, Zimbabwe 2000s, Venezuela 2010s-2020s, among others) was preceded by fiscal dominance — a state of affairs where monetary policy is subordinated to financing government deficits that cannot be financed by taxation or market-rate borrowing.
hyperinflation_requires_fiscal_dominanceinferred
viamonetary.monetary_expansion_directionmonetary.central_bank_independence
INCONCLUSIVE_DATA_PENDING — no outcome variable loaded; missing: ['hanke:hyperinflation_table']
run pending

Similar historical policies

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.

Argentine hyperinflation (1989-1990)
ARG·1989
match
1.9
monetary expansion directioncentral bank independence
Fiscal dominance and monetary instability
COD·1975
match
1.9
central bank independencemonetary expansion direction
CBN Ways-and-Means overdraft monetary financing
NGA·2015
match
1.9
central bank independencemonetary expansion direction
Peruvian hyperinflation (1988-1990)
PER·1988
match
1.9
monetary expansion directioncentral bank independence
Serial CBRT governor dismissals (Turkey 2019-2021)
TUR·2019
match
1.9
central bank independencemonetary expansion direction
Turkish 'low-rate vs inflation' heterodoxy 2021-2023
TUR·2021
match
1.9
central bank independencemonetary expansion direction
Yugoslav hyperinflation 1988-1989
YUG·1988
match
1.9
monetary expansion directioncentral bank independence
Belarus administrative price and directed-credit controls
BLR·1994
match
1.5
central bank independencemonetary expansion direction

References