Coauthor Esther Duflo, Michael Greenstone, MIT
The problem of the cooking stove is unexpectedly important: billions of people rely on open fires, or simple variations on that theme, for home cooked meals, but those fires are leading sources of pollution, with devastating consequences on health and the environment. The World Health Organization attributes nearly 2 million deaths a year (the leading environmental cause of death, and as much as malaria and tuberculosis combined) to “indoor air pollution from primitive cooking fires.” And cooking with biomass fuels (such as wood and dung) is a key source of greenhouse gases.
So, in recent years, economic development experts have touted the improved cooking stove, which can range from locally made clay ovens to metal appliances, as one of those remarkably simple solutions to a whole host of staggering problems.
Laboratory tests and field studies have made impressive claims for these stoves, including a reduction of carbon monoxide exposure of up to 60 percent. A huge global campaign, led by the Global Alliance for Clean Cookstoves with support from the U.S. State Department and the United Nations Foundation, is now calling for 100 million of the new stoves by 2020.To determine just how much this simple technology could improve
the lives of its users, Rema Hanna, together with Esther Duflo and Michael Greenstone of mit, began a multi-year study of a cook stove distribution campaign by an internationally recognized ngo in the underdeveloped Indian state of Orissa.
The simple stove, built using local materials, has an enclosed cooking chamber and a chimney designed to minimize the user’s exposure to the fire and smoke. It cost $12.50 to make and was heavily subsidized, so that households only paid about 75 cents.
While the researchers initially planned to study the effect of improved respiratory health on education and labor, they immediately began to notice that a smaller number of villagers than anticipated actually took up the ngo on the offer of the new cooking stove, and that those that did were soon not using the stoves as much as anticipated.
The results of the four-year study (of more than 2,500 households in 44 villages) surprised the researchers and have taken some of the steam out of claims made for this simple technology. People in the study, Hanna explains, did not value the new stoves enough and were reluctant to invest the effort needed to keep the stoves in good working conditions or repair them when they needed fixing.
By the third year of the study, as the new stoves deteriorated, households with those stoves were cooking an average of only 1.8 meals per week on the improved stoves, reverting to the traditional stoves for the rest of their meals. Consequently, while there was a significant effect on smoke inhalation in the first year, the effect disappeared in subsequent years.
Researchers also found that households with the improved stoves were experiencing a modest decline in living standards as they devoted time and effort to upkeep of the stoves. And there was no decrease in the amount of wood used and therefore no reduction in greenhouse gas emissions.
Hanna says the research has been important in showing how this technology is adopted and used (or not) over time. And, with large amounts of aid money being earmarked for improved stove distribution, the research is also a timely reminder of the need to assess new technologies thoroughly.
“Given limited funds for development,” Hanna says, “it would be preferable to spend it on things that have a proven record of success, while in the meantime continuing to conduct research on how to reduce the burden of indoor air pollution on the poor.”
— by Robert O'Neill