The Federal Reserve has announced that it will pump $600bn (£373bn) into the US economy by the end of June next year to try to boost the fragile recovery.

美联储宣布在明年六月份之前向美国市场注入6000亿美元资金来恢复其脆弱的经济。

This stimulus¹ equates² to $75bn a month, in a second round of "quantitative³（定量的，数量的） easing" (QE).

The US economy grew by an annual rate of 2% between July and September, which is not enough to reduce high unemployment.

Some analysts⁴ see QE as the last chance to get the US economy back on track.

The move was widely flagged, with most analysts expecting the Fed to inject $500bn into the economy.

For this reason, stock markets rose only slightly, with the Dow Jones closing up 26 points at 11,215, still enough to take the index to its highest level for two years.

Second step

Interest rates are already close to zero, which means the Fed cannot reduce rates any further in order to boost demand - the more traditional policy used by central banks to stimulate⁵ growth.

Instead, it has announced a fresh round of QE, in which it will create money to buy long-dated government bonds.

The programme has been dubbed⁶（被称为） QE2, after the Fed pumped $1.75tn into the economy during the downturn in its first round of QE.

It is in addition to the Fed's previously⁷ announced plan to reinvest（再投资） $250bn-$300bn of repayments⁸ it is due from existing US mortgage debt investments over the coming year.

The Fed said in a statement that the "pace of recovery in output and employment remains⁹ slow. Household spending is increasing gradually, but remains constrained¹⁰ buy high unemployment, modest income growth, lower housing wealth and tight credit".

It added that it would "regularly review the pace of its securities purchases and the overall size of the asset-purchase programme in light of incoming information".

One member of the Fed's Open Market Committee, which decides interest rates and QE, voted against the additional stimulus measures.

Thomas Hoenig argued that further stimulus could, over time, create inflationary（通货膨胀的） pressure and "destabilise（破坏，威胁） the economy".