But despite the lower bound, asset purchases and forward guidance can push long-term interest rates even lower on average than in the unconstrained case (especially when adjusted for inflation) by reducing term premiums and increasing the downward pressure on the expected average value of future short-term interest rates.
Thus, the use of such tools could result in even better outcomes for unemployment and inflation on average. Of course, this analysis could be too optimistic. For one, the FRB/US simulations may overstate the effectiveness of forward guidance and asset purchases, particularly in an environment where long-term interest rates are also likely to be unusually low.