Microfinance Insights tackles the social impact question in their latest volume: Panacea or Placebo: Evaluating the Impact of Microfinance.  The volume is a good read with diverse perspectives from, among others, Sam Daley-Harris on whether the number of households reached is more important than poverty reduction and Thomas Dichter on whether microfinance and business development are linked.

In the Research section, Jonathan Bauchet and I offer a simple guide that explains the mechanics of randomized experiments in microfinance.  We outline the merits and limitations of randomized trials along with the decisions and challenges faced by institutions during implementation. Our bottom line is that more evidence is needed to understand the effect of microfinance, and randomized experiments are beginning to prove themselves as effective tools to generate this evidence.