Would virtuous circles, or self-reinforcing growth, strengthen the case for aid? See here for a new paper with Patrick (Paddy) Carter: Virtuous circles and the case for aid.
Just added: a new literature review on regional growth and regional decline, co-authored with Holger Breinlich and Gianmarco I. P. Ottaviano. Comments and criticisms can be posted here.
Now available online: a review of the academic literature on foreign aid, published as a Handbook chapter. It was mostly written in 2007-8 and the final version submitted in the spring of 2009. I am likely to revise this material with a view to writing a book. Since the review is already 40,000 words long and on a complex topic, there are inevitably some mistakes and problems with it. If you are interested in aid, by all means let me know areas where you think the chapter should be corrected or revised, by posting comments here.