There exists a widely held (and frequently asserted) belief that there is a very big (relatively to other professions) discrepancy between the top tier software developers and the non-top-tier.
Examples from extremely reputable people include:
Paul Graham (in a bunch of his writings:  ,  )
... of superstars that produce ten times as much as the merely brilliant software developers.
Are there any studies supporting this? (e.g. that a "superstar" programmer would be 10x more productive than merely good programmer or 30-100x than average programmer respectively)
Just to clarify - I'm not asking if Joel was correct in naming 100x more productive developers "superstars" - that's his definition. I'm asking if there are enough such 100x more productive developers (100x on average) to warrant a separate class.