They were worried that if the discount rate is fifty basis points below the Federal Funds Rate then it's going to hit zero and that would be embarrassing; so they moved it.

他们担忧的是,如果贴现率比,联邦资金利率低五十个基本点,那么它将会接近零点,并且那将会很尴尬；所以他们改变了它。

耶鲁公开课 - 金融市场课程节选