American real GDP has actually grown faster when marginal tax rates have been much higher than they are now. That was back when we had something resembling a viable social contract.
It’s always good to recall how economic inequality correlates with many social pathologies by watching Wilkinson’s ted.org presentation again, with particular attention to his discussion of the Swedish case.
Market capitalism and globalization has fractured societies around the world, separating the global corporate elite from the common people. In my view, the countries that pull together the fastest will win in the long run because they will be happier and healthier and very possibly more productive.
For an inside view of how Romney views probably inequality, read Adam Davidson’s piece in the New York Times Magazine. “The Purpose of Spectacular Wealth, According to a Spectacularly Wealthy Guy.”