One of the earlier references to the 10x that I've found is in

https://www.scribd.com/document/557220119/NNPP-Article

> Researchers have found between a low of 5 to 1 to a high of 100 to 1 ratios in programmer performance. This means that programmers at the same level, with similar backgrounds and comparable salaries, might take 1 to 100 weeks to complete the same tasks. [21, p. 8]

> The ratio of programmer performance that repeatedly appeared in the studies investigated by Bill Curtis in the July/August 1990 issue of American Programmer was 22 to 1. This was both for source lines of code produced and for debugging times - which includes both defect detection rate and defect removal efficiency. [5, pp. 4 - 6] The NNPP also produces a higher instance of defects in the work product. Figure 1 shows the consequences of the NNPPs.

The reference to 21 is Shneiderman, Ben Software Psychology: Human Factors in Computer and Information Systems (Cambridge, MA: Winthrop, 1980) and 5 is Curtis, Bill, "Managing the Real Leverage in Software Productivity and Quality", American Programmer July/August 1990

https://archive.org/details/softwarepsycholo00shne/page/8/mo... - this then goes into an entire book of sources and research.

There's also mention of DeMarco and Lister in some literature... which means Peopleware.

From there:

> While this [10 to 1] productivity differential among programmers is understandable, there is also a 10 to 1 difference in productivity among software organizations.

> H. D. Mills, Software Productivity (New York: Dorset House Publishing, 1988), p. 266.

> Our study found that there were huge differences between the 92 competing organizations. Over the whole sample, the best organization (the one with the best average performance of its representatives) worked more than ten times faster than the worst organization. In addition to their speed, all competitors from the fastest organization developed code that passed the major acceptance test.

> This is more than a little unsettling. Managers for years have affected a certain fatalism about individual differences. They reasoned that the differences were innate, so you couldn’t do much about them. It’s harder to be fatalistic about the clustering effect. Some companies are doing a lot worse than others. Something about their environment and corporate culture is failing to attract and keep good people or is making it impossible for even good people to work effectively.

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

It means how many Mountain Dews you can chug per day.

Agreed. My developers go to eleven.