Some economists consider Social Mobility to be more important than inequality in a society's health. Apart from the United States, is there any civilization is considered to have more Social Mobility than any others? Why do theorists/historians think this is so?

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.