All of this changed in 2008, when a legislative reform allowed the Fed to pay interest on excess reserves. The commercial banks could sell Treasury bills and longer-term bonds to the Fed, receive reserves in exchange, and earn a small but very safe return on those reserves.
2008年改变了一切。立法改革允许美联储向超额准备金付息。商业银行可以向美联储出售美国国债和长期债券，换取准备金，并从中赚取小额但相当安全的回报。