I think you've confused what the meaning of PageRank is. Page Rank is a formula for working out the 'base' value of a site, for example a Wikipedia article being hosted on a very important (Page Rank) site will naturally rank higher then one that doesn't. As for an article on page 1 giving you more 'authority' then one on page 20, this doesn't work. Since the positioning of articles and results in a search engine is dependent on the search query, an article that might rank on page 1 for one phrase might rank on page 20 for another phrase.

Yes, an article with a high page rank (authority) will give you better results, but even this isn't a guarantee any more. If one of your articles gets shared a lot (Facebook etc) you might find that the authority increases for both the article and the site it links to - although that is just a theory on my part.

So to answer your question, for the most part they are equal. Mark.