In one of the book on "10x myth", the author bluntly states that there is no objective way to measure "productivity". So any such report is purely subjective. Its a fascinating argument. I don't remember the book, but this author had actually read the papers while researching and based his conclusion of the research papers
As far is reality is concerned, the differences between average and skilled can be as much as 100x or more. It can be even more if you consider that some people add negative productivity
This might have been “The Leprechauns of Software Development,” by Laurent Bossavit, which is one of my favorites. He digs into the sources behind a bunch of the popular sayings and determines that they’ve all been greatly exaggerated and/or misquoted.
As far is reality is concerned, the differences between average and skilled can be as much as 100x or more. It can be even more if you consider that some people add negative productivity