As an ex post instrument to put a burden on the originators of the crisis, such a tax might be justified. Nevertheless, as an ex ante steering tool, the proposed fund has major shortcomings. First, it would drain capital from banks. But, more importantly, it would not solve the moral hazard problem.
As the fund would act as lender of next-to-last resort for failing banks (the government would still have to step in if the fund’s resources were exhausted in a crisis), the problem would merely be shifted from the level of government to the level of the fund.