The Rate Is a Target, Not a Price

The Federal Reserve raised interest rates this week. That sentence is a useful shorthand and it is not a description of anything that happened.

What the committee voted on was a target range for one number: the federal funds rate, the rate banks charge each other to borrow reserves overnight. Nothing else was set, and that rate is not charged to any member of the public.

The word doing the work is target. No bank is obliged to lend at the rate the committee names, and the Fed cannot instruct one to. It has to arrange conditions in which the market arrives at the number on its own.

For most of the twentieth century that was done by scarcity. The Fed's own account of open market operations describes the method: buy securities from banks and the reserves in the system rise, making overnight money cheaper; sell them and reserves fall, making it dearer.

That worked while reserves were scarce enough for small changes to move the price. After 2008 the system held reserves measured in trillions, and adding or removing a few billion moved nothing at all.

So implementation was rebuilt around the administered rates it sets directly. The most important is the rate paid on reserve balances: what a bank earns for leaving money at the Fed overnight, risk-free, with no effort.

That rate sets a floor by making a simple comparison unavoidable. A bank will not lend reserves to another bank at less than it can earn doing nothing, so no lending happens materially below the administered rate.

Some institutions cannot earn that rate — money market funds, government-sponsored enterprises — and they would otherwise lend below the floor. The New York Fed's description of reverse repo explains the facility built for them, which offers those institutions a comparable risk-free overnight return.

Together the two rates form the bottom of the range. Above the top sits the discount window and the standing repo facility, where a bank short of cash can borrow against collateral, which caps how high the overnight rate can go before borrowers switch to the Fed instead.

The result is a corridor. The committee names a range, the administered rates hold the bottom, the lending facilities hold the top, and the market trades somewhere between.

Whether it worked is checkable each day. The New York Fed collects the previous day's actual transactions and the volume-weighted median is published every morning as the effective federal funds rate.

That number, not the committee's announcement, is the rate that exists. When it drifts toward the edge of the range, the desk adjusts, and a persistent drift is treated as a technical problem to be fixed rather than a policy signal.

This is also why the target is a range rather than a point. Before 2008 the committee named a single figure and the desk chased it with daily operations. A range acknowledges that control in an ample-reserve system is good but not exact, and removes the need to defend a decimal.

None of this yet touches a mortgage, a car loan or a corporate bond. The federal funds rate is an overnight rate between banks, and almost nothing a household borrows is overnight.

The connection runs through expectations. A thirty-year mortgage is priced off long-term yields, and a long-term yield is roughly the average overnight rate investors expect over the period, plus compensation for the risk of being wrong.

So what moves long rates is not this week's decision but what this week's decision implies about the next three years. A rise that markets already anticipated changes long yields very little, because the expectation was in the price before the vote.

This produces the result that confuses people most: mortgage rates can fall on a day the Fed raises. If the increase persuades investors that inflation will be contained sooner, the expected path of future overnight rates drops, and long yields drop with it.

The useful habit, then, is to read two documents rather than one. The statement says what the committee decided and why; the implementation note that accompanies it says what the desk has been instructed to do to make the decision real.

The second document is the shorter and it is where the mechanism lives — the level of the administered rates, the size of the reverse repo facility, the terms at which the Fed will lend.

The distinction matters for anyone trying to read the next few months. The decision is an announcement about intent. The target only becomes a rate when a few hundred institutions, each acting in its own interest, find that no better trade is available.