As a result, decisions to buy additional assets—and the resulting additional downward pressure on term premiums—were not offset by expectations of a higher path for short-term interest rates. The end result was that there was greater potential for asset purchases to have a discernible effect on longer-term yields in the years immediately following the financial crisis than in current circumstances.
17 See, for instance, James D. Hamilton, Ethan S. Harris, Jan Hatzius, and Kenneth D. West (2015), “The  Equilibrium Real Funds Rate: Past, Present, and Future,” NBER Working Paper Series 21476 (Cambridge, Mass.