Conventional monetary policies, designed to fulfill the Fed’s dual mandate of price stability and full employment, are ill-equipped to cope with the systemic risks of asset and credit bubbles, to say nothing of the balance-sheet recessions that ensue after such bubbles burst. This became painfully apparent in recent years, as central banks, confronted by the global financial crisis of 2008-2009, turned to unconventional policies – in particular, massive liquidity injections through quantitative easing (QE).
美联储目前的窘境的根源在于央行业务艺术和实践上的剧烈变化。为了满足美联储的两大职责&mdash;&mdash;稳定物价和充分就业而制定的常规货币政策无法处置资产和信用泡沫的系统性风险，更不用说这些泡沫破裂后持续的资产负债表衰退了。近几年来，这一点变得相当明显，面对2008&mdash;2009年全球金融危机的各央行纷纷转向非常规政策&mdash;&mdash;特别是通过量化宽松（QE）进行的大规模流动性注入。