> There is probably a ton of data already in different industries with regards to productivity.

Uh. Not really. Our industry is notoriously bad at measuring productivity.

And the bigger problem is that when we try to measure it - "performance review" - we like grading on a gaussian curve. We'll never know if that's correct because we put our thumb on the scale.

An even bigger problem is that productivity is strongly influenced by completely non-technical factors. How enthusiastic are folks about what they are doing[1], how much variety do their tasks have [2], what are their peers like, etc. (Of course, that whole field of study has issues rooted in the inability to measure precisely as well)

Ultimately, it's a squishy judgment applied by humans.

[1] https://www.semanticscholar.org/paper/What-Predicts-Software...

[2] https://research.google/pubs/what-predicts-software-develope...