Second, the wealthy are very good at keep their wealth for their families, those who are like them, those who went to the same school, etc.
The worse the disparity in income, the worse the economic mobility and the worse society is as a whole. It creates huge problems that are well documented and easy to see if you simply travel.
I understand Paul's point: driving technology creates wealth, and so it should be rewarded. Great. But if you peel off the fads and leave those technologies that really create wealth, you'll find Europe contributes just as well. In Europe, however, you don't trip over the homeless and crazy as you do in San Francisco. I'm an American entrepreneur; I choose to live in Europe.