Pope Benedict XVI has released his encyclical, Caritas in Veritate, which focuses on the current economic crisis and includes this tax policy proposal:

One possible approach to development aid would be to apply effectively what is known as fiscal subsidiarity, allowing citizens to decide how to allocate a portion of the taxes they pay to the State. Provided it does not degenerate into the promotion of special interests, this can help to stimulate forms of welfare solidarity from below, with obvious benefits in the area of solidarity for development as well.

(Hat Tip: Ted Afield.)