The problem now is that the natural interest rate – that is, the liquid safe nominal interest rate on short-term US Treasury securities – is less than zero. Thus, the central bank cannot push the market interest rate there.
如今的问题是自然利率——即短期美国国债的高流动性安全名义利率低于零。于是中央银行无法将市场利率调整到这一水平。除非自然利率有所提高，否则我们就会处于经济萧条中。