How has the microcredit movement managed to push financial frontiers? Theory shows that if borrowers vary in unobservable risk, then group‐based, joint liability contracts price for risk more accurately than individual contracts, provided that borrowers match with others of similar project...

In this paper, we contrast two different views in the debate on official dollarization. The Mundell (1961) framework of optimal currency areas and a model on boom-bust cycles, by Schneider and Tornell (2004), who take account of credit market imperfections prevalent in middle income countries....