I'm baffled by Martin's suggestion that the most important question here is whether the changes associated with borrowing are positive or negative rather than whether the changes are causal. How can it possibly matter what the effect is if there is no reason to believe in the proposed causal basis of the effect? If there is to be reflection and discussion of the impact of microcredit than that conversation should be held primarily around the Banerjee, Duflo, Glennerster et. al. Spandana study, the Banerjee, Duflo Al-Amana study and the Karlan, Zinman Philippines study which are much more likely to provide reliable evidence of causality, and not just around the PK vs RM debate.