"With Obama et al taking more and more of the fruits of our labor, why would these folks stay?"
Did you mean stay in NYC or stay in America?
Because most wealthy will stay in America because they know every other decent country has even higher taxes.
Canada? Australia? Europe? They have much higher taxes. Try Denmark for example, where the AVERAGE tax rate is fifty percent. You can imagine what the rich pay there.
But I suppose there's always Switzerland. LOL! Though they'll be changing theirs soon enough.