Sure, maybe you can get money to have some businesses try out rewriting their line-of-business software in the same language versus in a different language and get some results.
My expectation is that if you put the work in you can get actual hard numbers, which will promptly be ignored by every future person asking the same "question" with the same implied answer.
If the "just rewrite it and it'll be better" people were as right as they often seem to believe they are, a big mystery is JWZ's "Cascade of Attention-Deficit Teenagers" phenomenon. In this scenario the same software is rewritten, over, and over, and over, yet it doesn't get faster and doesn't even fix many serious bugs.
If the "just rewrite it and it'll be better" people were as right as they often seem to believe
Generally speaking, technological progress over thousands of years serves to validate this. Sure, in the short term we might see some slippage depending on talent/expertise, but with education and updated application of learnings, it's generally true.
My expectation is that if you put the work in you can get actual hard numbers, which will promptly be ignored by every future person asking the same "question" with the same implied answer.
If the "just rewrite it and it'll be better" people were as right as they often seem to believe they are, a big mystery is JWZ's "Cascade of Attention-Deficit Teenagers" phenomenon. In this scenario the same software is rewritten, over, and over, and over, yet it doesn't get faster and doesn't even fix many serious bugs.