The experiment started with the research team conducting training sessions with all loan officers in all branches of our collaborating MFI (which operates across all of Bosnia and Herzegovina). During these sessions officers were instructed how to identify clients they would normally reject, but to whom they would consider lending if they were to accept slightly more risk. Once all officers were trained, and following a pilot in November 2008 in two branches in Gradačac and Bijeljina, the experiment was rolled out two months later to all 14 branches of our MFI. Loan officers were now asked to start identifying potential marginal clients from the population of loan applicants over a period of several months, until the desired sample size was achieved. Once a loan officer identified a potential marginal client, and following a short vetting process by the loan committee, the potential client was told that although he or she would normally not qualify for a loan, our MFI was reviewing its policies and as a result could offer a 50 percent chance of a loan provided that the applicant would agree to participate in a survey now and in a year's time. The loan officer also explained that the MFI would use the results of the study to decide how best to expand lending to this new client group on a permanent basis, meaning that marginal clients could continue to borrow as regular ones. This process continued until a total of 1,241 marginal applications were submitted to the loan committee. In total 1,196 of these marginal loan applicants were approved and interviewed. The interview lasted around 60 minutes and was conducted by a professional survey company using computer-assisted telephone interviews (CATI). This baseline survey was conducted after the individual was judged to be eligible for participation in the program but before the randomization. At the end of each week, the research team in London would use a random number generator to allocate newly interviewed applicants with a 50 percent probability to either the treatment (receiving a loan) or the control group (no loan). Successful applicants received the loan within a week. Applicants allocated to the control group did not receive a loan from our MFI for the duration of the study. The last interview and loan disbursal took place in May 2009. During February-July 2010, 14 months after the baseline survey, all RCT participants - both those who received a loan and those who did not - were called back and invited to be re-interviewed. We returned to those who declined and offered them an incentive (a mobile phone SIM card). This further improved the final response rate.