How much domain authority is passed on through a link from a page with low authority?

[nyc-seo]

Hello,

Let's say that there is a link to site A from site B. The domain authority of site B is 85, but the link is on a page that has a page authority of only 1. Does much authority get passed along from site B to site A? (Let's assume site A has a domain authority of 35, if that's relevant.)

Thank you!

[nyc-seo]

Thanks, Federico.

[nyc-seo]

Thank you, Keri!

[nyc-seo]

Thank you very much, Dr. Meyers! This was extremely helpful.

[Dr-Pete]

Unfortunately, Dr. Matt's out of town, so this answer won't be as thorough as I'd like, but the gist of it is that we factor in both DA and PA to some degree. If a site has very high DA but a very low PA (as in your example), we're going to bias somewhat toward the DA, as we believe Google sometimes does (a virtually unknown page on Wikipedia can rank very well, for example). Likewise, a high-PA page on a site with low DA may pass more through the PA, because (hopefully) that page has some legitimate authority.

It's a bit more complex, because DA and PA are related as well, so they do influence each other to some degree. On larger sites, the influence of any single page's PA is small, but the influence can be more obvious on smaller sites.

Putting aside our math, I think a link from a low-authority page on a high-authority site can be worthwhile. Look at directories, like DMOZ. I think it's important to make sure the low-PA page is indexed (some DMOZ pages aren't, because they're buried so deeply in the link structure), and I wouldn't get hung up on a link from a high-DA site. It's ultimately just one link. I wouldn't dismiss it as useless either, though. There's some amount of site/page balance in the mix and Google doesn't rely on only one type of authority.

[Dr-Pete]

I'm checking with Dr. Matt Peters, head of our Data Science team. It's less about secrecy and more that DA/PA are based on machine learning and have gotten a bit complex. Still, I suspect we can give you a general sense of how DA/PA pass through links. Posting this because I suspect an answer may take a day or two.

[KeriMorgret]

Well, it is a bit late for regular office hours for most Moz staff, so you may not hear an answer until tomorrow. The answer may also include "remember, what the search engines think is what matters", but you should get an answer with at least some information in the next couple of days.

[MoosaHemani]

and I am sure Moz will not answer this at all!

[FedeEinhorn]

It is, but no one outside Moz can answer that, there are several metrics that affect authority passing, and I guess that most of those metrics and algos are property of Moz and most likely secret to prevent abuse.