AJ: Maternal mortality has been thought to be an unmovable problem, yet a recent study by The Lancet shows that several countries have made progress in its reduction. What, in your view, are the contributing factors?

NK: The study by The Lancet underscored just how much we don't know. It's quite remarkable that we don't have a grasp on how many women die from pregnancy complications each year. Is it 350,000 or 550,000? The data just aren't good enough to be sure, partly because no one counts dead mothers in many poor countries. I must say that I often see statistics in United Nations studies and elsewhere that claim a degree of precision that I find absurd.

For example, there's an often-cited statistic that one-quarter of young women aged 15 to 19 in the developing world are married (outside China). But in truth, in many poor countries, kids have very little idea how old they are and don't have birth certificates, so any age-related statistic is a wild guess.

In terms of reducing maternal mortality, my sense is that the big effort to train traditional birth attendants was pretty much a failure. It probably reduced neonatal mortality but didn't obviously save mothers' lives. But rural health systems have been improved, infrastructure has improved, vehicles and cell phones have become more common, and all these make it easier to rush a woman to a hospital when she's in obstructed labor. More broadly, I think some countries are now taking maternal health more seriously, and that perspective is trickling down to the villages.

AJ: Much of the funding for development targets specific health or social areas without addressing overlapping issues or systemic failure. But there's a trend now to address issues more holistically. Have you seen integrated development projects that work?

NK: The old stove-piping clearly didn't work very well. It was maddening that all the HIV funding meant that a woman could be treated for HIV but wasn't helped when she suffered from pregnancy complications. On the other hand, the drawback of the integrated approach is that it's expensive and it's hard to know what is cost-effective when you try a bunch of interventions simultaneously. I'm a huge believer in rigorous testing in randomized experiments, with careful measurement before and after. Monitoring and evaluation has traditionally been a weak area for nongovernmental organizations [NGOs], and humanitarians should be every bit as careful as for-profit businesses in ensuring that they get the most bang possible for the buck.

AJ: What are the benefits of working through the private sector in developing countries to improve women's health and overall well-being?

NK: Look, the private sector is incredibly good at distribution. If we could get condoms and bed nets into every village that serves beer, we'd save vast numbers of lives. The NGO world used to have a bit of disdain for business, but it's shedding that, and I think it is an important step forward. The private sector and NGO sectors can accomplish a huge amount if they work together.