American companies game the system in many ways, including shifting profits to overseas tax havens. In 2012, American companies reported more profit in low-tax Bermuda than in Japan, China, Germany and France combined, even though their employees in Bermuda account for less than one-tenth of 1 percent of their worldwide totals.
Over all, the share of corporate taxation in federal revenue has declined since 1952 from 32 percent to 11 percent. In that same period, the portion coming from payroll taxes, which hit the working poor, has climbed.
Clausing, Kimberly A., The Effect of Profit Shifting on the Corporate Tax Base in the United States and Beyond (January 11, 2016). Available at SSRN: http://ssrn.com/abstract=2685442 orhttp://dx.doi.org/10.2139/ssrn.2685442