The Impact of Central Bank Stock Purchases: Evidence from Discontinuities in Policy Rules -- by Masao Fukui, Masayuki Yagasaki

TEXT START: We trace the impact of central bank stock purchases by exploiting discontinuities in the Bank of Japan's policy rule, which triggers purchases when stock market index movements fall below a threshold.

The Dissection

The paper isolates the causal effects of Bank of Japan stock purchases across two monetary regimes. Its finding is brutally simple: purchases do not have a universal effect. When interest rates can move, they rise while stock prices do not respond detectably. Once yield curve control suppresses that adjustment channel, stock prices rise.

The text is really mapping where the financial system absorbs central-bank intervention. It is not demonstrating durable economic strength. It is documenting the rerouting of distortion: first into interest rates, then—after those are politically pinned—into asset prices.

The Core Fallacy

Relative to the Discontinuity Thesis, the central error is category confusion. The paper measures financial-market transmission and treats that as the relevant horizon of economic consequence. It is not.

A central bank can alter yields and inflate equities without restoring the mass employment → wage → consumption circuit. Asset-price support is not productive participation. It is a lag defense that preserves valuations, collateral, and institutional continuity while the underlying labor system remains exposed to P1, P2, and P3.

The paper’s evidence also destroys the fantasy that intervention is neutral. When one adjustment channel is blocked, the pressure migrates to another market. The state can move the pain; it cannot repeal the constraint.

Hidden Assumptions

• Financial-market stabilization is treated as economically meaningful even when it does not create necessary human labor.
• Higher stock prices are implicitly allowed to stand in for improved productive capacity.
• The institutional ability to keep purchasing assets is treated as durable rather than dependent on political legitimacy, fiscal capacity, and market confidence.
• Monetary transmission is analyzed inside a system whose employment architecture is assumed to remain intact.
• Distributional effects are largely absent: gains accrue to asset owners while non-owners receive no equivalent claim on productive power.
• The central bank is treated as an active stabilizer, not as a mechanism for managing the symptoms of declining returns and institutional fragility.

Social Function

Classification: partial truth and transition management, with a layer of prestige signaling.

The empirical result is real and useful. It exposes regime dependence in central-bank intervention and shows that yield-curve control changes who—or what—absorbs the shock. But its social function is narrower than its technical presentation suggests: it converts systemic deterioration into an elegant identification problem.

The graphs can show how the carcass is repositioned. They cannot show the carcass becoming alive. In DT terms, this is monetary hospice care: maintaining asset-market functionality while the productive-participation base erodes. It may buy time for Sovereigns, preserve collateral for capital owners, and create niches for transition intermediaries. It does not refute the terminal logic of automation.

The Verdict

This is a competent autopsy of central-bank plumbing, not evidence of systemic recovery. The Bank of Japan’s purchases demonstrate that policy can redirect financial pressure between yields and equities. They do not restore human economic necessity.

Under the Discontinuity Thesis, the result is a lag defense with diminishing returns. Once AI severs the labor-income-consumption circuit, central-bank purchases can stabilize the price of claims on the system—but not the system’s need for human participation. The intervention manages obsolescence; it does not prevent it.