Selected answers from the Dumb SEO Questions Facebook & G+ community.
Perry Bernard: Both. “Typical†link distribution is a weight toward the root or home page, but often specific pages might earn a bunch of links when others don’t. It all depends on what your are doing to earn them. The site as a whole will benefit in small part from any quality link shared to any page. I never use MOZ but i believe this is their algorithm for PA and DA. And of course they are trying to correlate that with Google’s view of links. It’s obviously not the same as Google though because nobody can tell you for sure.
Michael Martinez: The way a PageRank-like algorithm -MUST- work is that the link value is distributed virally document to document. You can`t have a site-wide valuation.
So, yes, the value of links pointing to document Alpha-1 is passed on to Alpha-2 and Alpha-3 through the links from Alpha-1, but there is no secondary valuation for all documents on Alpha by virtue of any Alpha document receiving links.
If Alpha-1 were to only link out to other documents NOT on the same site, then the rest of Alpha site would reap NO BENEFIT from those links.
That is why the use of "rel=`nofollow`" attributes on internal links is so dangerous and destructive.
Are backlinks specific for each page linked, or will quality backlinks for ex. domain.com also be positive for all sub pages, eg. domain.com/page1 ? 
