David Porteous Additional contact information David Porteous: David Porteous is Founder and Director of Bankable Frontier Associates, a consulting firm based in Boston, Massachusetts. The author wishes to thank the UK's Department for International Development (DFID), which financed BFA involvement in several projects that lead to some of the conclusions in this article; and CGAP, the Consultative Group to Assist the Poor (especially Tim Lyman, Gautam Ivatury and Mark Pickens), with whom Porteous has worked directly or in collaboration on many of the issues in this paper over the last three years.