I think the issue is: can one easily come and go from their current state to any one of a set of next best alternatives? For instance, your job as a software de

I think the issue is: can one easily come and go from their current state to any one of a set of next best alternatives? For instance, your job as a software dev, you could probably quit and and go be a teacher, or maybe you want to dig ditches, or maybe you want to be a blackjack dealer. Those things are probably all realistically attainable. Whereas, if you are sold into the sex trade and locked in a room, not able to shower for days at a time, you aren't able to swap careers as frictionlessly.