This Financial Times Editorial addresses the general lack of impact measurement within international development and the role of the Commitment to Development Index.
From the article:
The index always aimed to draw attention to a simple point: aid flows are not the be all and end all of a country's development commitment.
... It is astonishing that we still know so little about what sort of aid works. Donors - and their critics - are too quick to embrace the latest fashion and too slow to ask the hard questions about what really works in development.