Recall that the total tax bill for partners or officers of an LLC like Romney's Bain Capital or Warren Buffet's Berkshire Hathaway includes more than their personal income tax. Before payouts are made to owners or shareholders, the corporate tax must first be paid. I don't know the Bain-Romney accounting, but http://finance.yahoo.com/taxes/article/112560/what-top-companies-pay-taxes-forbes. Buffet apparently owns 23% of the company, controls 32%.
One would also have to factor that tax into wages offered and price of product.