Selected answers from the Dumb SEO Questions Facebook & G+ community.
Michael Martinez: It`s complicated. PageRank is calculated for the URL to which links point, but is calculated based on the links pointing to the URL.
If you`re noindexing a page then whatever PageRank would have flowed to it is (supposedly) evaporated back into the index. So in that respect you`re kind of walking away from or abandoning some potential PageRank inflow.
But PageRank doesn`t flow through every link. So all the links pointing to a page might be worthless. In that case, you`re not losing anything by noindexing the page.
And there is no way to know which links pass PageRank.
Nathan Nikolay Gaidy: It looks like there are much more impressions when errors are being fixed so I was wondering because it seems to directly affect traffic