是的，“U”型指的是未知的名义增长率。

Yes, type "U" refers to Unknown for the Nominal Annual Rate.

youdao

然而，仔细分析数据后表明，名义GDP飞速增长是通胀率上升的主要原因，但在能源冲击时期，如1974年至1980年，名义GDP增速实际上是趋于放缓的。

But a close look at the data suggests that the problem was mostly caused by extremely rapid nominal GDP growth, which actually tended to slow during energy shock periods like 1974 and 1980.

youdao

但很明显，一旦名义利率下降到零美联储会受约束，因此经济恢复到趋趋向增长率，但不会在金融冲击下恢复所受损失。

But obviously the Fed is constrained once nominal rates hit zero, and so the economy returns to its trend growth rate but never recovers the ground lost during the financial shock.

youdao

So we would say the real interest rate equals the nominal rate-- approximately equals--the nominal rate minus the inflation rate.

我们可以推出实际利率约等于,名义利率减去通货膨胀率

耶鲁公开课 - 金融市场课程节选

Remember, it's one and a half times inflation rate plus a half time the GDP utilization 1 plus 1.

注意，公式是，1。5倍通货膨胀率,加上0。5倍实际GDP与名义GDP的百分比,再加上恒常数。

斯坦福公开课 - 经济学课程节选