引述講稿
http://mikeon88.blogspot.com/2018/08/1321irr.html有人問不同公司是否給予不同本益比？
因有些公司本益比就是比較高。
不要，本益比固定，比較基礎一致才能比較貴淑。
最終本益比設多少都沒關係，設成1萬倍也可以，
只要所有股票標準一致即可。
Is the PER different for each company? Yes, the PER can vary across different companies, and some companies may have higher PERs than others. However, a fixed PER can be used as a consistent basis for determining whether a stock is cheap or expensive. The actual value of the PER doesn't matter as long as it is the same for all stocks being compared, even if it is set at a high value like 10,000 times.
本益比高或低往往是十年河東，十年河西的事。
微軟在90年代本益比30倍，
2010年代則掉到10倍，因獨占地位受到Android 挑戰。
PER often changes every 10 years. For instance, Microsoft's PER was 30 times in the 1990s. However, in 2010, it dropped to 10 times due to the challenge posed by Android to its monopoly position.