The Efficacy of Large-Scale Asset Purchases at the Zero Lower Bound
研究了美联储在金融危机期间通过大规模购买长期国债来降低长期利率的效果，发现公告后长期国债收益率立即显著下降，但部分经济学家对此有不同看法。
During the recent financial crisis, the Federal Reserve took unprecedented actions to prevent the economy from collapsing. First, the Federal Open Market Committee (FOMC) lowered the short-term federal funds rate nearly to its zero lower bound. Then, several months later, the FOMC began making large-scale purchases of long-term Treasury bonds to lower long-term interest rates by reducing the supply of long-term assets. The FOMC’s announcement of its intent led to immediate and substantial declines in the yields of long-term Treasury bonds. While these results suggest that changing the supplies of bonds available to the private sector brought about the changes in prices and, in turn, long-term interest rates, some economists disagree. Most economic models of the term structure of interest rates, including the widely known expectations theory, assume that supply shifts of bonds do not matter in determining prices.