From Larry Summers:
The US should eliminate the distinction between repatriated and unrepatriated foreign corporate profits for US companies and tax all foreign income (after allowance for taxes paid to other governments) at a fixed rate well below the current US corporate rate of 35 per cent, perhaps about 15 per cent. A similar tax should be imposed retrospectively on accumulated profits held abroad.
Such a proposal could easily be designed to raise revenue relative to the current baseline, encourage the repatriation of funds to the US, and reduce the competitive disadvantage faced by American multinationals. It is a fair compromise between businesses and reformers. It is as close to a free lunch as tax reformers will ever get.