I'd love to see some research on this. I would hypothesize that there is a point of problem complexity where the lack of tests becomes a negative for productivity.
I second this suggestion (and agree with the hypothesis, although its probably not just a function of raw problem complexity, other variables must come into play)
Hasnt it been done already? Couldnt find anything I would class as 'scientific' with a quick google search. Would be a good thesis for someone.
