This position reflects only one possibility and one that likely misses the mark by a wide margin. Perhaps those left behind should pay the taxes avoided by those who have fled to tax havens. If one group of citizens is politically able to use the fiat power of the state to force everyone to pay taxes to fund projects valued highly only by members of that group but abhorred by everyone else, welfare is enhanced by increasing the taxes on the former and reducing taxes on the latter. Tax havens do not create mobile capital. The real problem is high taxes and oppression.
High taxes reduce the return to owners of capital and labor.
Either way, the impact of high taxes is welfare-reducing. By implication, then, the impact of tax havens is unmistakably welfare-enhancing. This is information that political leaders need to have in order to make fully informed decisions about tax policy. Full information is a sine qua non of efficient decision-making. Key factors used by the OECD in identifying and assessing harmful preferential tax regimes include no or low effective tax rates, lack of transparency, and lack of effective exchange of information.