This analysis by Jia Yang explains that large U.S. companies with operations abroad pay far less in U.S. corporate income taxes than they used to. For instance, Yang writes, in 1969, corporate giant Procter and Gamble (based in Cincinnati) paid 40% of its total profits in U.S. corporate income taxes, while today it pays about 15%. She explains that this effective lowering of the corporate tax rate has occurred because big companies have far more operations abroad, and they can shift their income to places where U.S. tax law operates more lightly. Worth reading.
Why can’t The US be like Australia and charge taxes based on income?