Is microfinance going the same way as subprime mortgages?

THE notion, popularised by C.K. Prahalad’s best-seller, “The Fortune at the Bottom of the Pyramid”, that poor people should be seen as potentially profitable customers rather than mere charity cases, has caught on fast in the past few years. Finding profitable ways to meet the needs of poor people, the idea goes, would not only empower them by making them customers rather than supplicants, it would also attract far more capital than would ever be forthcoming from charity. For the providers of this capital, catering to the bottom of the pyramid promised to be good for the soul as well as the wallet.

A growing number of investors have taken the chance, investing in bottom-of-the-pyramid businesses, of which by far the most popular to date is microfinance—providing loans and other financial services to people ignored as too poor by the traditional banking system. Yet as this idea has spread, it has become increasingly controversial. …