That’s an extremely strong statement to make without extensive examination of the actual data and studies by people using the actual data. Really, the first thing you try and find is the magnitude of impact which give exactly what you say is impossible to find.
On an anecdotal basis only, which sounds more plausible, then:
1) Murder rates are 4x lower chielfy/solely because of unleaded gas
or
2) Murder rates are 4x lower because of quite a few qualitative observations that we think data would confirm each played a role.
It's like saying, "I think murder rates are higher in Norway compared to Sweden not because of some big societal difference between the two countries, but probably because I remember a news story where a depraved lunatic shot 90 kids on an island."
I can’t let this go. It’s nothing like that. Yes, you are just positing opinions as if they’re facts, but that’s not everyone. There has been reviews of the literature. E.g I can’t recall the book off the top of my head but something like out 120 studies on effectiveness of different policing strategies, only ~20% of studies showed statistical significant effects for any given strategy and a fair amount of those failed to replicate. Meanwhile we’ve continually had studies pointing to lead as a significant driver with significant effect sizes. You keep strawmanning this “solely” argument that no one is making while also ignoring the plethora of data pointing to it being a huge driver, and by the far the largest driver with any body of evidence. It’s not like this stuff isn’t being studied, yet I challenge you to find studies that can show anything near the evidence for these other factors.
