Is that internal or external link juice? I have the impression that my main website is slowly recovering from Panda since I started doing intensive internal link building.
Not easy to explain without visual aids but...
Try not to think of this as internal or external nor think in terms of PageRank... link juice propagation is best understood through architecture and as such internal links can both bolster and hamper page quality regardless of what value external links deliver.
There are two completely different thought processes commonly associated with SEO architectures.
Since PANDA (as Google explains) is distinguishing between high & low quality content let's stick with that and call these SEO high & low architectures. Low Quality Architecture:
is about repetitive anchoring on a specific page pointing similar styled anchors to other pages. High Quality Architecture:
is about succinct anchoring on a specific page allowing each new link generation (above or below) to gain prominence by compounding values of partial matches.
If the target is Search Engine Optimization (poor example but gets the point across)
Page 1 Search
Page 2 Engine
Page 3 Optimization
You can also do
Page 1 Search
Page 2 Search Engine
Page 3 Search Engine Optimization
But in the latter you limit yourself in the realm of longtail targeting which is where PANDA is killing domain pages off... and because of the loses associated with low level pages all the internal links back to top level pages also disappear which compounds the traffic loses.
BTW... IMHO PANDA is Supplemental Results in drag