Yield Curve Control: How Central Banks Cap Yields

Key Takeaways

• The BoJ ran YCC from September 2016 to March 2024, widening the 10-year JGB band from near zero to plus or minus 1.0 percent before abandoning both YCC and negative rates in one meeting.
• YCC sets the yield and lets the market set the quantity, unlike QE, where the central bank sets the quantity and the market sets the yield.
• The RBA's April 2020 three-year YCC target failed in late 2021 when the market pushed yields above 10 basis points, forcing abandonment without a controlled exit.
• YCC emerged in WWII-era U.S. at Treasury's request to finance war spending, the same fiscal context worth monitoring in future proposals.

What It Is

Under conventional QE, a central bank announces a pace or total of bond purchases and lets the market determine the resulting yield. Under YCC, the central bank announces the yield it wants on a specific maturity and stands ready to buy without limit to defend it. The most cited recent example is the Bank of Japan, which in September 2016 announced a target of around 0 percent on the 10-year Japanese government bond (JGB). The band evolved from tight in 2016 to plus or minus 0.25 percent in 2018, plus or minus 0.50 percent in December 2022, plus or minus 1.00 percent in mid-2023, and was effectively abandoned in March 2024.

Two other modern cases are the Reserve Bank of Australia's April 2020 to November 2021 target of 10 basis points on the three-year Australian government bond, and the United States during 1942 to 1951, when the Fed capped Treasury bill yields at 0.375 percent and long bonds at 2.5 percent at Treasury's request to finance the war.

The Intuition

QE is a blunt instrument: you set the quantity, the market sets the price, and the two can diverge when expectations shift. YCC flips that. By committing to buy any volume at the chosen yield, the central bank forces the market to accept its view. If investors believe the commitment is credible, volumes traded in defense often fall, because no one wants to sell into a guaranteed bid above or below their fundamental view.

The tradeoff is sovereignty over the balance sheet. Defense of the peg can force very large, open-ended purchases precisely when the policy becomes contested. Exit tends to be messy because markets front-run the removal of the bid.

How It Works

A YCC regime needs three operational pieces:

1. Target maturity and target yield (e.g. 10Y JGB ≈ 0.0%, band ±1.0%)
2. Unlimited fixed-rate purchase offers at the ceiling yield
3. A communication framework explaining conditions for change

The BoJ combined YCC with a negative short-term policy rate of minus 0.1 percent and with forward guidance. When long yields pressed the upper band, the BoJ would announce daily fixed-rate purchase operations offering to buy any volume at 0.25 percent, then 0.50 percent, then 1.00 percent as bands widened. The RBA used a similar fixed-rate buying structure.

Abandonment usually happens in two steps: widen the band, then drop the target and shift to conventional rate policy. The BoJ widened from 0.25 to 1.00 percent in 2022 to 2023 as global yields rose, then in March 2024 ended both YCC and negative rates in one meeting. The RBA missed its defense in late 2021, abandoning the target after the three-year yield spiked well above 10 basis points.

Worked Example

Assume a central bank targets the 5-year yield at 1.00 percent with a plus or minus 0.25 percent band. Global inflation surprises higher, and the 5-year yield drifts to 1.25 percent. To hold the ceiling, the central bank announces a daily fixed-rate operation offering to buy unlimited 5-year bonds at 1.25 percent.

In the first week, it buys $60 billion as hedge funds sell into the bid. If it holds, short positions close and volumes drop in week two. If instead inflation prints accelerate and speculators judge the commitment unsustainable, volumes balloon. Suppose weekly purchases move to $150 billion, then $300 billion. Within a month the balance sheet has grown by $500 billion or more, and the central bank faces a choice: widen the band, abandon the target, or accept a much larger balance sheet than it planned. This is exactly the dynamic the BoJ faced in late 2022 and mid-2023.

Common Mistakes

1. Treating YCC as a softer QE. It is the opposite. QE lets the market set yields given a quantity. YCC sets yields and lets the market set the quantity, which can become very large.
2. Ignoring FX consequences. A peg on long yields pins the cost of capital but not the currency. The yen weakened sharply against the dollar in 2022 to 2023 in part because rate differentials widened while YCC capped Japanese yields.
3. Assuming exit is symmetric with entry. Entering YCC is often orderly. Exiting is rarely so. Both Australia and Japan saw disorderly repricing as credibility eroded.
4. Confusing YCC with Operation Twist. Twist was a duration reshuffle at a fixed balance-sheet size. YCC is open-ended quantity at a fixed price on a chosen maturity.
5. Forgetting the fiscal context. YCC tends to emerge when fiscal authorities need cheap long-term financing. WWII-era U.S. caps were introduced at Treasury's request, which is a pattern worth remembering when evaluating future proposals.

Frequently Asked Questions

What is yield curve control and how does it differ from QE? Under QE, the central bank sets the quantity of bonds to purchase and lets the market determine the yield. Under YCC, the central bank sets the target yield and commits to buying unlimited bonds to defend it, the market determines the quantity. YCC is a price instrument on a specific maturity; QE is a quantity instrument across maturities.

How long did the Bank of Japan run yield curve control? The BoJ introduced YCC in September 2016, targeting the 10-year JGB at approximately 0 percent. The permitted band widened several times, to ±0.25% in 2018, ±0.5% in December 2022, and ±1.0% in mid-2023, before YCC was effectively abandoned in March 2024 alongside the exit from negative rates.

What caused the Reserve Bank of Australia's YCC to fail? The RBA set a 10 basis point target on the three-year Australian government bond in April 2020. When global inflation surprised higher in late 2021, the market pushed yields well above the target. The RBA failed to defend the peg and abruptly abandoned it in November 2021, an uncontrolled exit that damaged the bank's credibility and illustrates the risk of YCC commitments under rising inflation.

Why does YCC often coincide with a weaker currency? YCC pins the domestic cost of capital at an administered level regardless of global rate moves. When other central banks raise rates, the interest-rate differential widens against the YCC country. The yen's sharp depreciation against the dollar in 2022 and 2023 was partly driven by this dynamic: the BoJ's yield cap held Japanese long-term rates near zero while U.S. rates rose to 5 percent.

When has the U.S. used yield curve control? From 1942 to 1951, the Fed capped Treasury bill yields at 0.375 percent and long bond yields at 2.5 percent at the Treasury Department's request to finance World War II. The Fed eventually reasserted monetary independence in the 1951 Treasury-Fed Accord, which ended the peg and established the principle that the central bank should not be subordinate to fiscal financing needs.

Sources

1. Bank of Japan. "New Framework for Strengthening Monetary Easing: Quantitative and Qualitative Monetary Easing with Yield Curve Control." September 21, 2016. https://www.boj.or.jp/en/mopo/mpmdeci/mpr_2016/k160921a.pdf
2. Bank of Japan. "Changes in the Monetary Policy Framework." March 19, 2024. https://www.boj.or.jp/en/mopo/mpmdeci/mpr_2024/k240319a.pdf
3. Bank for International Settlements. "Yield Curve Control." BIS Working Papers. https://www.bis.org/publ/work977.htm
4. Reserve Bank of Australia. "Review of the Yield Target." Research Discussion Paper 2022-01. https://www.rba.gov.au/publications/rdp/2022/2022-01.html
5. Federal Reserve Board. "International Finance Discussion Papers." https://www.federalreserve.gov/econres/ifdp/

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.