One thing the stats don't show, and I'm quite curious about, are those who are wealthy but seek greater (or even continue to seek) opportunities. The bulk of taxes don't tax wealth - they tax income (and gains on wealth like capital gains, interest and dividends get treated differently depending on where you go). Perversely, the rich have the luxury then to be subsidized for certain parameters because they don't need to pay for what they see as the benefits of living in that given place.

For this reason, you can get some remarkable statements like the year that Warren Buffett said something to the effect that there is something wrong with a system when his secretary gets taxed as a percent more than he does. Of course, we later learned this was somewhat disingenuous given most of his income wasn't personal income at all but dividends (http://www.timesonline.co.uk/tol/money/tax/article1996735.ec...).

This being said, how is your comment relevant to the startup visa? The idea as I understand it would be to attract those without money but who need it from VC's - and as you say, the US is often the destination of choice for those like that. The point being to attract great entrepreneurs from countries that don't welcome them - at least a number of countries being a case in point: http://www.foreignpolicy.com/story/cms.php?story_id=4095&... - "In one 2005 poll, just 36 percent of French citizens said they supported the free-enterprise system, the only one of 22 countries polled that showed minority support for this cornerstone of global commerce. In Germany, meanwhile, support for socialist ideals is running at all-time highs—47 percent in 2007 versus 36 percent in 1991."