Case Study 2 — Why Didn't the 2009–2019 QE Cause Inflation?

Between 2008 and 2014, the Federal Reserve expanded its balance sheet from about $900 billion to $4.5 trillion — creating trillions of dollars of new money through quantitative easing. Classical monetarists predicted this would cause high inflation. Many financial commentators predicted hyperinflation. "The Fed is printing money! Inflation will soar!"

It didn't. Inflation from 2009 to 2019 averaged about 1.7% — below the Fed's 2% target. The prediction of QE-driven inflation was among the most spectacularly wrong forecasts in modern macroeconomics.

Why?

What the quantity theory predicted

MV = PY. The Fed increased M enormously (through QE asset purchases that created new bank reserves). If V and Y were constant, P should have risen proportionally. The quantity theory predicted high inflation.

Why inflation didn't happen

1. Velocity collapsed. The newly created reserves mostly sat in banks as excess reserves — they did not circulate through the economy. Banks, traumatized by the 2008 crisis and facing stricter capital requirements, held the reserves rather than lending them out. The velocity of money (V) fell sharply — from about 1.7 (M2 velocity) in 2008 to about 1.1 by 2019. The increase in M was almost exactly offset by the decrease in V. MV was roughly unchanged, so PY was roughly unchanged.

2. The economy was in a liquidity trap. Interest rates were at zero. Businesses and consumers didn't want to borrow, even at very low rates, because demand was weak and the outlook was uncertain. The usual transmission mechanism (lower rates → more borrowing → more spending → inflation) didn't operate. The money the Fed created stayed in the financial system rather than flowing into the real economy.

3. Bank lending was constrained. New regulations (Dodd-Frank, Basel III capital requirements) required banks to hold more capital. Banks tightened lending standards. The money multiplier — which translates reserves into broader money supply — was much smaller than normal. The Fed created reserves, but banks didn't multiply them into loans.

4. Inflation expectations were anchored. Because people believed the Fed would eventually withdraw the stimulus (which it did, through "tapering" QE and eventually raising rates in 2015), expectations of future inflation stayed near 2%. Anchored expectations prevented the money creation from translating into price increases.

What the episode teaches

The quantity theory is a long-run framework, not a short-run prediction machine. In the long run, sustained money growth does cause inflation. But in the short run, the relationship depends on velocity, banking system behavior, and expectations — all of which can offset changes in the money supply.

Liquidity traps are real. When interest rates are at zero and the economy is depressed, creating more money doesn't necessarily stimulate spending. The money just piles up as bank reserves. Keynesian economists had predicted this; monetarists were skeptical. The 2009–2019 period vindicated the Keynesian view.

The comparison to 2020–2021 is instructive. When the government combined monetary stimulus (QE) with fiscal stimulus (direct payments, enhanced unemployment benefits, PPP), the money did reach consumers and businesses. Consumer spending surged, supply was constrained, and inflation finally arrived — four years after the monetarists had predicted. The lesson: QE alone (which puts money in banks) didn't cause inflation. QE + fiscal stimulus (which puts money in people's pockets) did.

Discussion questions

  1. "The Fed printed trillions and nothing happened." Is this accurate? What DID happen to the financial system, even if inflation didn't rise?
  2. Why was QE alone insufficient to cause inflation, while QE + fiscal stimulus was sufficient?
  3. Some economists argue that QE inflated asset prices (stocks, bonds, housing) without inflating consumer prices. Is asset-price inflation a form of inflation the CPI misses?
  4. If the quantity theory doesn't work in the short run, should we abandon it? Or is it still useful for the long run?
  5. The 2020–2021 fiscal stimulus did what QE alone couldn't — it put money in people's hands. Does this mean fiscal policy is more powerful than monetary policy during a liquidity trap?