What I'm describing is an accounting trick. If you take an average, then make it smaller, then compare it back to the original average, there will be a differen

What I'm describing is an accounting trick. If you take an average, then make it smaller, then compare it back to the original average, there will be a difference. Not clear how you are connecting this to the broken window theory, which as a side note, while often used fallaciously is not a fallacy in itself.