Do new residents get shares? If so, how do you deal with dilution? Seems like that would become a reason to want to keep people out.
It would be unwise to give all new residents shares, for the reason that you point out. But you would want them to be able to buy shares at market rates. And maybe you also give shares to some class of people who move in, reside a long time, do a certain amount of volunteering, etc.