Nancy Birdsall posts at Views from the Center. She is thinking about constructing:
...a measure of the quality (beyond the quantity) of the aid programs of the major donors. We have some initial ideas, building on the measure already used in our Commitment to Development Index: extent to which aid is tied, extent to which it goes to countries with honest, accountable governments, and more...
We are assessing the feasibility of other measures: How much aid goes through multilateral channels (and should we consider that a good thing?) How much aid is "poverty-focused"? On the ground in recipient countries, is donor country X coordinating with donor country Y (and UN and World Bank, etc.) --or colluding or competing or just part of a well-intentioned cartel, and does that make sense?
We discuss some of these ideas in The Market for Aid. Generally, the idea of a performance table or ratings for aid agencies seems like a good idea to me. Donors could expand successful agencies and close down unsuccessful ones.
The Center for Global Development have done some good work on this already, but what's most striking to me is how little we know about which donors and agencies are doing the best job.