It took a few months, but Google Executive Chairman and former CEO for many years has finally joined Google+. The company has been under some criticism lately because most of its top people were not active on the site.
People like Vic Gundotra and Bradley Horowitz, who lead the Google+ effort were active on the site, to a degree. Other Googlers from further down the ranks were very engaged as well.
But, even though both cofounders, Larry Page, now CEO, and Sergey Brin had set up accounts, they have not been very active lately.
As for Eric Schmidt, he didn't even have an account. Even the
Dalai Lama beat him to it.
That
changes now and he has already posted a couple of public things. He may be more active inside his circles, but that's the beauty of Google+, there's no way of knowing, unless you're part of Schmidt's circles.