one is to look at the sequence of event, look at these sequence in October 29, stock market crashed, two month later, 9% unemployment peaked at 9%.

一种是看看事件发生的时间，看看顺序,10月29号，股票市场崩溃，两个月后，失业率上升到。

斯坦福公开课 - 经济学课程节选