The collapse of Lehman Brothers in 2008 drove up risk premia and triggered panic in financial markets, weakening assets in the United States and elsewhere, and threatening to provoke a credit crunch. In order to avoid asset fire-sales – which would have led to the disorderly unraveling of private-sector balance sheets, possibly triggering a new “Great Depression” or even bringing down the eurozone – advanced countries’ central banks began to purchase risky assets and increase lending to financial institutions, thus expanding the money supply.
2008年雷曼兄弟公司的倒闭推高了风险溢价，引发了金融市场恐慌，打击了美国和其他国家的资产，并产生了信贷动荡危险。为了避免资产大甩卖——这会导致无序的私人部门资产负债表崩溃，引发新的“大萧条”甚至欧元区解体——发达国家央行开始买入风险资产、增加面向金融机构的贷款，从而扩张了货币供给。