One of the persistent questions about sustainable development is how to help the world’s poorest people. Their incomes are so low that they lack access to the most basic goods and services: adequate nutrition, safe drinking water and sanitation, and life-saving health interventions. One strategy, which I have long favored, is to provide targeted financial support to help the poor to meet their basic needs and thereby to escape from the poverty trap. My colleagues and I have calculated that the cost of ensuring basic life-saving health coverage for the world’s poor would be around 0.1 percent of the gross national product of the high-income countries (10 cents per $100 of income).  

One example of such targeted aid is a mass free distribution of antimalaria bed nets to people living in impoverished malarious regions of Africa. Each of these long-lasting insecticide-treated nets (LLINs) costs only around $10 to produce, transport and distribute to households in rural Africa. Because the nets last for five years and two children typically sleep under each net, the cost per child per year is a mere $1.* Even at this remarkably low cost, however, some critics have opposed such an approach. They have claimed that the nets would “go missing” in large numbers because of waste by recipients and others in the supply chain who did not properly value them. These critics’ preferred solution is market sales of nets at a discount rather than a massive free distribution, on the grounds that even a small price would encourage more efficient use of the nets. 

Yet there are too main arguments in favor of mass free distribution. The first is that the poorest people simply cannot afford to pay $10 per net. The second is that there are important spillover benefits (or “positive externalities”) when a person uses a bed net, because the net not only gives personal protection to the user but also helps to block transmission of the disease within the community. We should therefore encourage very high levels of bed net use, just as we do with immunizations.

This is one of those interesting cases in which both experiments and real life have now provided evidence to resolve this debate convincingly: the case for mass free distribution of bed nets has proved to be stunningly powerful. On the basis of experience and key public health concepts, official global policy has now adopted mass free distribution of anti-malaria LLINs as the global policy. As a result, after many years in which bed net coverage was extremely low, it is now soaring, and malaria cases are falling sharply in those places in Africa where mass bed net distribution is being deployed.   

Here is how the events have unfolded. Evidence has long shown that Africa’s rural poor are so destitute that many are unable to pay even a tiny amount for lifesaving health interventions, even when the costs are subsidized. Not surprisingly, attempts to sell them subsidized LLINs during the years 2000 to 2005 fell badly short, even at prices as low as $2 to $3 per net. The uptake of bed nets in Africa through sales was very small, and coverage remained a tiny fraction of those in need. As of 2005, before the start of large-scale free distribution, one million children or more continued to die each year in Africa of a largely preventable and wholly treatable disease.

Beginning in 2002 and 2003, the International Red Cross and UNICEF began experimenting with a mass free distribution of LLINs in some trial sites. They found that the logistics of mass free distribution were indeed feasible, that community uptake was high, and that distributed bed nets were indeed in the households in high percentages upon spot checks of the recipient communities a few months after the mass distribution.

The evidence of success of mass distribution continued to grow. The World Health Organization adopted mass distribution as its basic standard in 2007. In a Global Malaria Action Plan, the international partnership on malaria control known as Roll Back Malaria set a goal to distribute around 300 million LLINs in Africa through free mass distribution during 2008-2010, in order to cover all sleeping sites in malaria-transmission regions. Already, as the result of mass distribution, the coverage with long-lasting insecticide treated bed nets has jumped from perhaps 10 million in 2004 to 170 million nets as of the end of 2008.

Recently the Poverty Action Lab at the Massachusetts Institute of Technology carried out a detailed experiment in Western Kenya that compared mass distribution with a partial-subsidy approach. The results: even a small charge for bed nets led to a tremendous drop in their adoption. Moreover, there was no greater wastage of the nets received for free than for the nets that were purchased at the discount price. The conclusion of the M.I.T. study was clear: “Free distribution is both more effective and more cost-effective than cost-sharing.”

The Roll Back Malaria Partnership has now embarked on a coordinated effort to ensure comprehensive malaria control throughout Africa that includes not only anti-malaria bed nets but also medicines, rapid diagnostic tests and community health workers trained to deliver such vital interventions. The cost will be around $3 billion per year, or $3 annually for each of the one billion per person per year of the one billion people living in the high-income donor countries.   

There are three lessons here. First, the poorest of the poor are in such dire straits that failures to help can lead to needless mass suffering and deaths. Even interventions that seem to be nearly free from the U.S. perspective, a few dollars per household per year, can be a financial barrier for the poor. Second, mass free distribution of bed nets, medicines, and vaccines can be highly effective and properly managed. Third, documented demonstration projects and careful experiments, working hand in hand, have improved the rigor and success of malaria policies, and those successes should now be taken to full scale.    

For more background on these distribution programs, please see the readings posted on

*Erratum (10/01/09): This sentence has been edited since posting to state the correct cost of mosquito nets.