Subdomain and domain authority

[smorrison]

I have Domain A (main content site, lots of content), with a domain authority of 91, and Domain B (blog of the first site, lots of content), with a domain authority of 82.  I'm merging the blog into the main domain.  Would it be best to keep it as a subdomain, or under a directory?

[Marcus_Miller]

In general terms, your blog is always better off on the main site as that is where all your linkable content is likely to live so the main site benefits from the link juice from the blog. That is a high level view from like 10,000 feet but as a general rule of thumb, always do

www.mainsite.com

www.mainsite.com/blog

Hope that helps!
Marcus

[smorrison]

Thank you, Marcus.  That was my initial thinking as well, but I've been hung up on how the existing domain authority and inbound links to the blog -- which is currently on its own domain -- will impact the main site's domain authority if we move it to a subdomain or to a folder of the main site.

Since the blog has solid domain authority now, and many quality inbound links, will my main site suffer when all of those now-external links from the blog become internal links, or will it benefit from the external links that once pointed to the blog on its own domain?

About 12% of the blog's traffic comes from the main site, whereas 1.5% of the main site's traffic comes from the blog. So I could assume that the main site would benefit from the link juice of all of those new inbound links -- right?

Put another way, if we combine content from two sites having a 10 point difference in domain authority, do you think the resulting domain authority will go up or down?