There is, however, a lively debate about whether there was a fourth big mistake: Alan Greenspan’s decision in 2001-2004 to push and keep nominal interest rates on US Treasury securities very low in order to try to keep the economy near full employment. In other words, should Greenspan have kept interest rates higher and triggered a recession in order to avert the growth of a housing bubble?
然而还存在另一场活跃的争论，也就是是否存在第四个重大错误：2001年至2004年期间，艾伦·格林斯潘决定下调并维持美国国债的名义利率，使其处在很低的水平，以此试图保持经济体的近乎充分就业状态。换言之，格林斯潘是否应该将利率维持在一个更高的水平上，给过热的经济降降温，以避免房地产市场泡沫的增长？