If this question is off-topic, my apologies. It seems borderline to me.
I have had several people tell me (without reference) this idea that:
Enforcement is ineffective because enforcement will only change behavior in the presence of the enforcer.
I have asked them for their source but I never get any. I also do not see it in my preliminary searches.
So, I am wondering if anyone here knows the origin of this statement or any research which supports such a claim.