In the boring old real ‘analogue’ world, ideas of authorship and authority naturally sit together. Over time we work out who is talking sense and who is full of hot air.
While I can work on simple hypotheses like ‘if this is written by Melanie Phillips it is almost certainly ghastly rubbish’, a search engine like Google has to calculate authority through a dense mix of keyword density, social cues, link quality, time on page, speed of hitting the back button, etc, etc.
That’s hard work - which is why Google is now starting to account for authorship in its algorithm. It is identifying content by author, and is starting to calculate the authority of different authors. So all things being equal, if Delia Smith and Jamie Oliver are both writing about breakfast, the author with the highest authority will rank higher and (cue drumroll) bring home the bacon.