David Roodman's Microfinance Open Book Blog

• .@GiveWell:"rethinking how we use cost-effectiveness estimates for which the calculations and methods are not public" http://t.co/2SOi83mK #

In March, Mark Pitt leveled two major charges at the attempt by Jonathan Morduch and myself to replicate the Pitt & Khandker assessment of microcredit. Both charges highlighted discrepancies between our version of the statistical analysis and the original. One of those was that we left out a control variable (this post explains the error without excusing it). The other I will explicate now in a nontechnical way.

You may know that when I began my inquiry into microfinance I found myself drawn into scrutinizing what were then the leading studies of the impact of microcredit. The strategy was to reproduce ("replicate") those studies on my own computer as well as I could. In 2009, I wrote a paper with Jonathan Morduch that built on his earlier work in this vein, and argued that the leading studies had not, after all, succeeded in measuring impacts.

Due Diligence is set for release on January 5 (more about the launch event soon). Before then, you can pre-order the book and get a 25% discount. And the book includes a dozen of my favorite blog posts, at no extra charge to you!