Several big categories of mechanisms have been successfully introduced, in which government can play multiple roles, including direct levying of funds (via development-directed taxes), facilitating or channelling private voluntary contributions, and acting as a guarantee to further allocation of private funds. Taxes do not represent one of these big categories of initiatives. There is considerable potential for private voluntary financing when consumers purchase goods and services, which could be better coordinated with public action (leverage). States could also play a larger role in providing incentives (tax instruments) and guidance.