One of the best ways to create wealth is to use currently existing capital in a more efficient manner, which is what the banking industry does.
I do believe that I agreed on this one (see post 80) already. However, there isn't anything unique that ties banking to NYC other than history. To believe that NYers have some special expertise that isn't found elswere is unrealistic.
The business with the fence was to make a point about what is produced vs what is consumed in NYC. My point being that NYC wealth is very dependent on the rest of the country and not really produced in NYC. If you cut NYC off like Cuba and made it an independent country (and the majority of New Yorker voters have the same view of frededom that Castro has) then it would be impoverished PDQ.