The Fed primarily thinks through the lens of interest rates — the flow of money from the future into the present. Think of it as shaping a waveform: if the slope is too steep, money rushes into the present and causes inflation. If the slope is too flat, money dries up and a crisis looms. The neutral rate where the economy neither expands nor contracts is r* (r-star), and the entire apparatus of central banking is an attempt to keep the waveform near that neutral slope.
Simple Picture
Money exists across time. You can hold it now (cash) or send it into the future (buy a Treasury bond). Interest rates are the price of this time travel. When the Fed lowers rates, it makes sending money into the future expensive — the future does not pay you enough to wait — so money stays in the present and gets spent. When the Fed raises rates, the future becomes attractive, money flows forward, and present spending slows.
But the Fed cannot force money to go where it wants. Money always finds a way around the barriers. Lower rates are supposed to encourage lending and spending, but the money can chase asset prices instead, making people feel rich without directly increasing economic activity. This is the two-economies problem: the Fed shapes the waveform, but the waveform splits into financial and real channels that respond differently.
The Architecture of Money
In a functional system, all pseudo-dollars and dollars are interchangeable:
Physical currency — 100 bills held abroad. The least important form of money for the system.
Bank deposits — the number in your bank account. This is an IOU from your bank to you, not “real” money. Bank deposits are not loaned to others; loans are created out of thin air, with the deposit appearing simultaneously as the bank’s liability and the loan as its asset.
Central bank reserves — real digital dollars held by banks at the Fed. Only banks can hold reserves. These are the settlement layer that makes bank-to-bank transfers work.
Treasuries — debt of the U.S. government, backed by nothing but faith. For the very wealthy, treasuries are the only form of “money” that makes sense: FDIC limits cap at $250K, you cannot own reserves directly, and hoarding physical cash is impractical. Treasuries are the savings account of the ultra-rich and of foreign central banks.
Treasuries have a fluctuating market value even though they are “stable” if held to maturity. This fluctuation is the price of instant liquidity. If all the money is chasing some shiny new thing, you have to discount your treasury to compete for attention. But when money starts drying up and treasuries are the only arks remaining, their price rises. The liquidity extrinsic in action — the same asset changes price based purely on how desperately the market needs liquidity.
Interest Rate Mechanics
The Fed controls short-term rates directly but has less influence over long-term rates. The toolkit:
Federal funds rate — the overnight rate. Traditionally controlled via reserves, but after QE flooded banks with reserves, this mechanism broke. Now the Fed uses two levers: interest on reserves (paying banks to park money) and the reverse repo facility (paying money market funds to not move their money). The RRP is essentially a widely available interest-paying checking account — it sets a floor on rates because all other loans must compete with the risk-free alternative of parking cash at the Fed.
Longer-term rates — the Fed buys longer-dated treasuries, which increases their price and lowers their yield. This increases the cost of sending money into the future, encouraging it into the present. The transmission mechanism: banks and individuals are encouraged to make more loans, and money chases asset prices, creating a wealth effect. But neither directly increases economic activity — only fiscal spending does that.
The eurodollar futures market bets on what the Fed will do in the near future (3 months out) and is often correct even when the Fed makes plans in the opposite direction. The market prices in the Fed’s actions before the Fed takes them — the information asymmetry is reversed, with the market knowing the Fed’s moves better than the Fed knows the market’s response.
An inverted yield curve — short-term rates higher than long-term rates — indicates the market expects a crisis soon. It represents a premium for locking up money during a time of potential trouble, compounded by the flattening effect of Fed purchases on long-term rates.
Shadow Banking and Systemic Risk
The shadow banking system — money market funds, ETFs, mortgage REITs, private investment vehicles — functions like banks but without the same regulatory protections. Money market funds are like bank deposits for the shadow world. ETFs and mortgage REITs are shadow banks because of their redemption mechanisms — they promise instant liquidity backed by assets that are not instantly liquid. The maturity mismatch that kills banks also kills shadow banks.
In 2008, the shadow banking world was falling apart simultaneously:
There was a run on the primary dealers, there was a run on the money market funds, there was a run on the securitization vehicles, and there was a run on the hedge funds. The commercial banks were not safe either, because they were deeply intertwined with the shadow banks.
Bear Stearns, a primary dealer, was refused repo loans when news of their subprime exposure hit. They had to offload assets at fire sale prices, which cascaded to all financial institutions. The Fed could not normally lend to primary dealers, so they created a new emergency window — improvising the rules in real time to prevent systemic collapse.
Shadow banks increase the amount of risk that the Fed cannot fix without emergency powers. Each new shadow banking entity extends the system’s reach while reducing the Fed’s control — more leverage, more maturity mismatches, more potential runs, all outside the regulatory perimeter.
The 2020 Treasury Run
In 2020, people wanted dollars and tried to sell their treasuries — the one asset that is supposed to be equivalent to cash. While 2008 was about the sudden discount of MBS, 2020 was about the sudden discount of treasuries. The system cannot afford a “final settlement” run — if everyone tries to convert their pseudo-dollars into actual dollars simultaneously, the interchangeability breaks and the entire architecture collapses.
This is the deepest fragility: the system works because nobody tests it. All the layers of money — deposits, treasuries, reserves, money market shares — are treated as interchangeable precisely because nobody tries to convert them all at once. The load-bearing fiction is that these are all “the same thing.” The 2020 treasury run showed that under stress, they are not — and the Fed had to intervene to restore the fiction by buying treasuries and providing the liquidity that the market could not.
The Central Bank Put
Many participants believe in a central bank “put” — the implicit promise that the Fed will step in to prop up prices and avoid a crisis. This belief is self-reinforcing: if everyone assumes the Fed will rescue the market, they take more risk, which creates the conditions that will require a rescue. The Minsky mechanism at its purest.
The bond market is usually considered smarter than the equity market because bond investors are incentivized to make sure their money gets paid back — they reflect fundamentals sooner and faster. The equity market is the most emotional, the most talked about, and the most susceptible to the central bank put. With low cost of debt from QE, companies leverage this to buy back shares and increase EPS even when net income is unchanged — financial engineering that increases upside per share but also increases loss per share.
Foreign central banks like China’s have no way to invest their dollars in anything other than treasuries or reserves. Private sector assets carry too much risk and are not deep enough. This is why the dollar hegemony is self-reinforcing: the architecture of the global financial system channels foreign savings into U.S. treasuries, which keeps rates low, which enables more borrowing, which produces more dollars that foreign central banks must recycle back into treasuries.
Dimwit / Midwit / Better Take
The dimwit take is “the Fed prints money — that’s why we have inflation.”
The midwit take is “the Fed manages interest rates to balance growth and inflation using sophisticated models.”
The better take is that the Fed is not managing the economy — it is maintaining the interchangeability of multiple forms of pseudo-money, any one of which could trigger a systemic crisis if the market stops treating it as equivalent to dollars. The interest rate is just the most visible lever. Underneath, the real work is ensuring that bank deposits stay equivalent to reserves, that treasuries stay equivalent to cash, that money market shares stay equivalent to deposits. Each of these equivalences is a load-bearing fiction that works only because the Fed stands behind it. The moment any equivalence breaks — as MBS did in 2008 and treasuries briefly did in 2020 — the cascade begins. Central banking is less like steering a ship and more like maintaining the belief that the ship is seaworthy while quietly patching leaks faster than water comes in.
Main Payoff
While central bank reserves are backed by assets (treasuries), and treasuries are backed by nothing but faith — and as the central bank holds more treasuries, it too is backed only by faith. The circularity is the point: the system is self-referential, each layer of money trusting the layer below it, and the bottom layer trusting the top. The stored time in the system is preserved by this circular trust. Break any link in the chain — let any form of money become visibly non-interchangeable with the others — and the entire architecture of deferred consumption collapses. The central banker community is tight-knit for a reason: they are the maintenance crew of a machine whose continued operation depends on nobody looking too closely at the engine.
References:
- Joseph Wang, Central Banking 101