What is quantitative easing?
Quantitative easing (QE) is a central bank creating new money to buy financial assets — overwhelmingly government bonds — in order to stimulate the economy when conventional interest rate cuts have reached their limit.
Why it exists. A central bank's normal tool is the policy interest rate. When that rate is already near zero, it cannot be cut much further — the zero lower bound. QE is what central banks turned to after 2008 when they had run out of conventional room.
How it works mechanically:
The central bank creates reserves electronically — new central bank money, not printed notes.
It buys bonds in the secondary market, mainly from pension funds, insurers and banks.
Bond prices rise and yields fall. Because bond prices and yields move inversely, large-scale buying pushes yields down across the market.
Lower yields feed through to borrowing costs generally, and push investors toward riskier assets seeking return — the portfolio rebalancing effect.
Sellers hold cash instead of bonds, which they may spend or invest.
Confidence and expectations are also part of the intended mechanism.
What it is not. It is not the government printing money to fund spending directly, which would be monetary financing and is prohibited in most advanced economies. The central bank buys existing bonds in the market, and the purchases are assets on its balance sheet that can be sold or allowed to mature.
The criticisms, which are substantial:
Asset price inflation. Pushing up the price of bonds, shares and property benefits existing asset holders disproportionately, and QE has been widely criticised for worsening wealth inequality.
Uncertain effectiveness on the real economy, with the transmission to lending and investment weaker than hoped.
Pension deficits widened by lower yields.
Difficulty unwinding. Quantitative tightening — reversing it — has proved awkward, and central banks have taken losses on holdings bought at higher prices.
Its relationship to inflation remains contested among economists.