I applaud the effort to try and dissect the problem scientifically.
If a whole program has 1 bug due to being implemented with dynamic types over static types, and that bug has gone unnoticed, then it can't be particularly important.
The other common proposition is that dynamically typed languages are faster to write in than statically typed languages. If this is true then we need to compare the saving in development time with the cost of the bugs which go undetected.
My gut feeling says that this line of analysis is never going to prove that static typing in inherently "better".
If a whole program has 1 bug due to being implemented with dynamic types over static types, and that bug has gone unnoticed, then it can't be particularly important.
The other common proposition is that dynamically typed languages are faster to write in than statically typed languages. If this is true then we need to compare the saving in development time with the cost of the bugs which go undetected.
My gut feeling says that this line of analysis is never going to prove that static typing in inherently "better".