I don't want to come across as anti-unit-test or anti-studies but I suggest you run your own study and gauge your own performance rather than assuming you and y

I don't want to come across as anti-unit-test or anti-studies but I suggest you run your own study and gauge your own performance rather than assuming you and your team perform as an average team does. Thanks to the version control tools we use this is easy. Adopt a policy where you commit code for a SINGLE reason at a time. Enumerate a few standard reasons such as BUGFIX, FEATURE, FEATURE_AND_UNIT_TEST, REQUIREMENTS_CHANGE, UNIT_TEST_MAINTENANCE. Estimate the engineering time that was spent on making the change. Log that duration. Periodically analyze your performance and see for yourself how much time unit-testing is costing or saving you.