Does PR decrease when google's index increases?

Has anyone experienced a PR decrease with increase in google's index

[mil2k]

Read in the original PR paper that the sum of all pages on the web will always be equal to one. According to me this means that as google increases it's indexed page's database we have to keep up with it by our link popularity campaign otherwise our PR can drop. Can anyone share experiences over this? Is this a correct interpretation?

[troels nybo nielsen]

I think it is correct, yes. And I have seen it for my own websites:

The "Boston" update gave me a PR drop for many pages: My two PR6 pages both dropped to PR5 and many PR5 pages dropped to PR4, but my positions in SERPs generally got better.

[mil2k]

So next time google announces a mojor update in Index i have to frantically start a link campaign. Interesting.

[troels nybo nielsen]

Not necessarily. Remember that if the growth in Google's database causes your PR to drop, the same reason will cause your competitors to drop too.

But of course it is always a good idea to get more inbound links. Relevant links. From quality sites.

[whatson]

Your actual PR may drop but relatively it will remain the same.

[doc_z]

There is no easy answer to that question.

If the new pages have non-significant inbound and outbound links then the situation doesn't change very much. PR of the old pages will be nearly unchanged. However, this model isn't very realistic. In practice there are significant changes and they would led in most of the cases to a decrease of your PR. But not necessarily to a change in ranking.

Even if the PR will remain the same this doesn't mean that the ToolbarPR is the same. The scale of the ToolbarPR can change. One (of two) point of fixing this scale would be probably fixing the highest PR value (e.g. with TollbarPR = 11.0). Therefore, a change of this value can led to a change of your ToolbarPR (not of the PR). Of course, ranking is not effected.

By the way: The sum of all pages on the web will be only equal to one if there are no dead ends, i.e. pages/documents with no link on it. There are a number of such pages thus the average is lower than one. However, this is not important since the situation for the "old pages" is probably nearly the same as for the new added pages.

[Jane_Doe]

One of my sites had a lot of the internal pags drop in PR in the last update. So did many of the pages of external links. I noticed many of the PR6 links dropped to 5s.

However, the rankings went up in for most keywords for this site and traffic is up from the month before, and that's what really matters.