I am not sure how it is effected, but I have heard that it does not help thus I try to have sites with unique content. However there are many sites that are just pure copies of others that somebody has mass produced and they often have good PR so maybe not.
I am not too sure whether duplicate content affects a site's PR but it runs the risk of incurring a penalty from Google in the form of suffering lower search engine rankings as a result.
With duplicate content, the rankings (and PR) are split among the pages that have the dup content. Therefore, your content has less value and that brings everything down. The goal is to have unique, relevant content on each page. That way, the SEs see that as being important and give more value to it.
I respectfully disagree. SE's do penalize duplicate content but not by splitting PR. PR is a measure of link popularity and has nothing to do with duplicate content. The usual penalty for duplicate content is removal to the supplemental results (pages with low pagerank end up there as well). Even if a page is still in the main index duplicate content affects negatively its ranking, and often it doesn't matter whether the page is the origin or not, dupes can outrank it if they have higher PR or other ranking factors in their favor.
well duplicate site doesn't help your sites' pr... but if you change the header and some inside contents then you should be ok.
I think what should be noted is that dup content will bring you no advantages while you could have filled the space within unique content that does bring a benefit. As suggested rewording the content is possible but if you are already doing that, why to paraphrase from multiple articles on a particular topic and create your own article. It depends if your running the website primarily for the user, or for profitability. Google hits that their dup detection is quite sensitive so one could assume that changing a word here and there is not enough.
That is correct kiddies.... .. from this article on Duplicate Content issues PR is based on BackLInks.. duplicate content issues will NOT affect your PageRank