Motivated by this concern, the Fed has held the nominal short-term interest rate near zero – its effective lower bound – for more than five years, with a promise to keep it there until 2015, and has been purchasing about $1 trillion of long-term government bonds each year. As a result, the nominal yield on the ten-year Treasury bond, a widely used measure of the federal government’s borrowing costs, hovers around 2%.
出于这一担忧，美联储在五年多的时间里一直将名义短期利率维持在近零水平——它的实际下限，并承诺一直如此直到2015年。此外，美联储每年还购入约1万亿美元的政府债券。结果，十年期美国国债名义收益率——广泛使用的联邦政府借贷成本指标——一直在2%徘徊。这比2012年的历史低点1.4%高些，但只有2008年前水平的不到一半，40年平均水平的三分之一。以真实值衡量，短期和长期利率均为负。