It's on a per page basis. So if google thinks the same article on a different domain is more important, it will rank that page better then yours.
dcristo is right. If it is just one article, the more authoritative site will get higher ranking for that article. However, if your site is full of duplicate content, than you know what that means.
Yes, if Google discover multiple pages with duplicate content, you can sure expect a Red Flag! Write some genuine, good content of 'VALUE'...Google will love it, so will your audience..and you'll be rewarded with higher SERP's and thereby a greater flock of searchers... Or you can outsource quality content writers...But that's entirely your choice!
Sure if you exaggerate with the duplicate content I think that will compromise your entire site rankings. If it's just a few pages, you have nothing to worry about. Google will just ignore them.
1. It's lose not loose - two different words, two different meanings. 2. http://www.google.com/support/webma...er=66359&query=duplicate+content&topic=&type=