http://microfinance.cgap.org/2008/12/08/is-more-credit-always-good-credit/

The sub-crime crisis happened despite credit bureaus and information sharing across financial institutions. I don’t believe that these measures by themselves are adequate to avoid a crisis. The MFIs in due course may just start making larger loans. The added in complexity in microcredit is that the clients and loan officers are of significantly lower educational level than what we saw in the sub prime crisis.Moreover microloans are non-collateralized which means in case of massive defaults it could wipe out MFIs.
Given that some of the equity investors expect nearly 40% per annum return on investment and MFIs are on trying to grow extremely fast and spread their geographic operations far and wide to give these returns to investors, I anticipate that some of these MFIs are likely to be challenged to maintain sane internal controls.
In Bangladesh the biggest MFIs are non-profits or member owned and perhaps they could more easily realign their organization to social goals rather than just making loans whenever client overindebtedness rose. In India they are for-profit institutions largely owned by PE funds/ VCs. It will be interesting to see how the large MFIs in India respond to these emerging challenges.

Bhalchander