The quantitative easing monetary policy in the United States, also known as quantitative easing (QE), is an unconventional monetary policy tool implemented by the Federal Reserve. Quantitative easing is mainly to cope with economic difficulties during the financial crisis or economic recession, and to stimulate economic growth by increasing the money supply.

Specifically, quantitative easing monetary policy mainly includes the following aspects:

1. Expand the balance sheet of the central bank: The Federal Reserve increases the base money supply by purchasing a large number of financial assets (such as treasury bonds and mortgage-backed securities) and injects a lot of liquidity into the market.

2. Lower interest rate: By lowering the federal funds rate (the benchmark interest rate set by the Federal Reserve), lower the interest rate of the whole financial market, thus encouraging enterprises and individuals to borrow and consume, and stimulating economic growth.

3. Raise inflation expectations: Quantitative easing often leads to an increase in the money supply, which may lead to inflation. Moderate inflation helps to stimulate economic growth, because people will feel the pressure of currency depreciation, thus accelerating consumption and investment.

In American history, quantitative easing monetary policy was used to deal with the economic recession caused by the financial crisis in 2008 and the COVID-19 epidemic in 2020. However, quantitative easing policy also has some risks, such as asset price bubbles and inflation. Therefore, when the Federal Reserve implements the quantitative easing policy, it needs to make prudent decisions according to the economic situation and financial market conditions.