I can't access the article so I will respond to only the title.
I use a rough threshold of how much responsibilities they can, or, have to endure, and manage to take care of in a good enough way.
By far the best response here so far. But since we don't have clear definition and my threshold may be vastly different than yours, its anyone's guess.
By far the best response here so far. But since we don't have clear definition and my threshold may be vastly different than yours, its anyone's guess.