The US, where consumption accounts for the bulk of the shortfall in the post-crisis recovery, is a case in point. In an environment of excess debt and inadequate savings, wealth effects have done very little to ameliorate the balance-sheet recession that clobbered US households when the property and credit bubbles burst.
量化宽松的真正症结在于牵引。在美国，消费是危机后复苏疲软的主要原因，这正说明了牵引因素的重要性。在债务过多和储蓄不足的环境下，财富效应对于改善资产负债表衰退作用甚微。当房产和信用泡沫破裂时，资产负债表衰退令美国家庭遭受重创。事实上，2008年初以来年化平均真实消费增长率只有1.3%。当前，真实GDP复苏每年大约在2.3%——比过去周期的正常水平低两个百分点——很难认为对量化宽松的普遍赞扬理所应当。