In the drug case people are not self-selected, because anyone can easily become a trafficker himself.
Same for the gun regulation case.
However, as soon as there is a legal structure that exerts regulation, it's very hard, basically impossible, to enter the regulatory institution. This staticness is one of the reasons, regulatory institutions fail after some time - Quis custodiet ipsos custodes?
But that's exactly what I meant with self-selection: anyone can choose to become a power figure in an unregulated market. How did you interpret self-selection?
Yes, regulatory bodies require maintenance and vigilance both to remain effective and to maintain an accessible market. Neither is a fundamental argument against regulation.
Same for the gun regulation case.
However, as soon as there is a legal structure that exerts regulation, it's very hard, basically impossible, to enter the regulatory institution. This staticness is one of the reasons, regulatory institutions fail after some time - Quis custodiet ipsos custodes?