People are quick to paint this as Facebook twisting the screw, but do we know definitively, not speculatively, that this is an intentional and planned effect, l

People are quick to paint this as Facebook twisting the screw, but do we know definitively, not speculatively, that this is an intentional and planned effect, like there's some variable somewhere that determines what percentage of a page's fans will see a post before it stops being shown? Why can't it just be due to the growth of Facebook? There's more content competing for eyeballs, the way consumers engage with Facebook has probably changed over time, people may be following more pages than they used to, and so on.