It’s hard to prove a law that has a deterrent effect, since you can see the number of people it “caught” but the people it deterred are invisible.
The best proxy for the deterrent effect is how much criminals need to pay to launder money. I can’t find a good source on this, but some anectdata that put it between 15-50%.
I mean, sure, but if you're demanding detailed statistics from the anti-side (the start of this thread), letting the pro-side gesture vaguely in the direction of hard to measure deterrence seems like an isolated demand for rigor.
