Does Google penalize for dead links?

Lots of them in non-commercials..

[IITian]

I am looking for links in a non-commercial area and unlike commercial categories where, I assume, each link is checked regularly, many of these sites have vast number of outward links dead. I guess, a sign of neglect.

1. How does this affect the PR transfer/voting? If there are 100 outgoing links out of which 70 are dead, does Google transfer PR assuming there are only 30 (number of live links) outward links?

2. Since Google is big on quality of user experience, and dead links are frustrating to the users, does this mean Google reduces PR of pages containing dead links?

[doc_z]

As far as I know:

1. No
This depends on Google's implementation of the PR algorithm. In principle both methods could be used, i.e. either calculate the PR only on pages which are in the index or considering all links. As far as I know, even non-existing links are considered. For example, www.google.es is showing PR4.

2. No
At least PR is not more reduced than linking to (existing) dead end pages, i.e. pages with no outgoing links.

[Mohamed_E]

... many of these sites have vast number of outward links dead. I guess, a sign of neglect.

Definitely a sign of neglect. I try to run Xenu on my sites once or twice a month, and often catch pages that have died (or gone to a 301) since the last scan.

There is no evidence that Google currently uses any "page quality" metrics, but it is very possible that at some time they will do so. Popups would be another obvious target of any "page quality" metric.

[Napoleon]

These are actually very good questions. I must say I HOPE that there is no negative effect, as I have just purchased a site with hundreds of dead links - it will take an age to update them all.

From my experience though, there is no penalty.

[IITian]

doc_z

Thank you. That's what I thought even though I was hoping that the calculations don't include those dead links.

Mohamed_E

It is remarkable to see high PR sites with about 70% of outward links dead - apparently for years. Wish there was a hacker software that changed those dead links to links to my sites. It won't be hurting them at all. ;)

Napoleon

I think so too.