All true. I would add US prison time is arbitrary, not based on data. Locking someone up for 5 years is extreme but another state will, for the same crime lot up 20 years. Does 5 years reduce crime the same as 20 years. You might think sure the guys on the street 15 years less. What if the folks locked up for 5 are less likely to reoffend?
The EU data suggests we lock up folks too long.