It's pretty easy to find various papers/studies about TDD, unit testing, and the like by searching online but I would not call any of them scientifically or emp

It's pretty easy to find various papers/studies about TDD, unit testing, and the like by searching online but I would not call any of them scientifically or empirically rigorous. Given the lack of any objective or agreeable standards regarding what "code quality" means, these papers can draw conclusions to support any view.