I've started learning about blockchains, a fairly new technology, and specifically the possibility that they can function as a platform for markets for Social Policy Bonds. This suggestion has been made by two of my correspondents in the past few days; it's a new idea, and my first thought is that it's an exciting one. The blockchain principle allows us to bypass government (or whoever issues the bonds) when it comes to monitoring progress toward goal achievement. It facilitates payments made to those who help achieve the objective; a role that I have thought might have to be played by a coalition of holders of large numbers of the bonds making decisions as to which projects are likely to be most efficient. This link is to a short article showing how the blockchain principle is being applied to searching for a cure for HIV. Though it talks about a Social Impact Bond, if I surmise correctly the tradeability of the bonds means that they are in fact Social Policy Bonds - perhaps the first ever to be issued.
Update 12 March: there is a discussion about implementing Social Policy Bonds in Ethereum here.