[davidw]

Here's the paper:

http://links.jstor.org/sici?sici=0002-8282(199805)88%3A2%3C62%3ASASMAT%3E2.0.CO%3B2-8

Unfortunately it's not free. The stats cited in the book are that only 20% of the top 100 from 1915 were still there in 1995. Think about the technology landscape 100 years ago, and how much it's changed. I think there's every chance that Google will either not be around, or be radically smaller or different than it is now. It could be even larger, too. It's simply not possible to know. What is evident though, is that with time, companies grow and die.

Bonus fact - this is one of the oldest companies in the world:

http://en.wikipedia.org/wiki/Zildjian