A study that captures a correlation instead of causation directly is not completely useless. It seems wise to try to draw some conclusions from the massive cor

A study that captures a correlation instead of causation directly is not completely useless. It seems wise to try to draw some conclusions from the massive corpus of OSS software that is available given that it's hard to imagine any researcher will ever get the budget to do even one controlled test on a meaningfully sized software project. Anyway, it's not hard to imagine an improved version of the study that knows about the years of experience of each contributor (even if that necessitates reducing the size of the dataset a bit) and controls for it. I suppose that would be the "empirical software engineering" equivalent of econometrics.