There's an appendix to one of the chapters in Jeremy Siegel's book where he says that one of the most important applications of this theory is to measure how successful an investor is.

刚才讲的是,杰里米·西格尔书上的附录,他认为这个理论最重要的应用,就是衡量一个投资者的收益

耶鲁公开课 - 金融市场课程节选