If you take two sites with modest page rank (one is a PR4, the other a PR3) and merge them together, how likely is it that they will enjoy any sort of consolidated boost in link juice / page rank?
I am particularly asking about "link juice" and the ability to improve rankings, as opposed to just purely increasing the reported numeric page rank value in the PR toolbar.
On the other hand, how likely is it to tank rankings?
Both are ecommerce sites that have been foundering in google search over the last several years. Their products are not particularly complimentary (one is apparel, one is decor). On the other hand, they USED to be all on one site and were split into two sites back in late 2009.