Marketing Stoves Through Social Networks to Combat Indoor Air Pollution in Bangladesh
Every year nearly two million children under five die from acute respiratory infections, the leading killer of young children.1 Epidemiological studies have identified environment hazards, such as indoor air pollution, as a key culprit for these infections. Indoor air pollution, which is mainly caused by the burning of wood, dung, and other biomass fuels within the household particularly affect women, who are primarily responsible for cooking, and young children who often spend time with their mothers. Despite the potentially devastating health consequences, it is not understood why vast numbers of rural households continue to use potentially harmful cooking practices when relatively cheap alternatives are available. It is possible that households are unaware of the health consequences of indoor air pollution, are unable to afford cleaner stoves or fuels, or are averse to adopting new cooking technologies, which may be less well suited to their customs or taste.
Ninety percent of households in rural Bangladesh use biomass fuels, which could adversely affect the health of inhabitants, for both cooking and heating.2 In 2008, 14 percent of deaths in children under-5 were a result of pneumonia.3 This study, which aims to reduce indoor air pollution, took place in two districts that varied both demographically and in their fuel needs. Hatia is an isolated island in the south of the country. The region is poor compared to the rest of Bangladesh, but has relatively easy access to fuel-wood. Jamalpur is a densely populated region in the north of the country, with very little access to fuel-wood, and instead use animal dung, and agriculture residues such as straw, rice husks, sugarcane refuse, and jute sticks.
Researchers evaluated the impact of providing households with incentives to purchase one of two locally designed cleaner versions of the cooking stoves. The stoves were locally designed so as to keep them as similar to the traditional cooking stoves as possible. The first option was a chimney stove, at a cost of Tk 750 (approximately US$10.50), and the second was a portable stove, at a cost of Tk 400 (approximately US$5.60). These costs are equivalent to approximately one to two weeks' wages. A chimney stove is convenient because it can still be used indoors, funneling smoke outside. The portable stove increased fuel efficiency, but does not decrease emissions.
Households were randomly assigned to one of eight different treatment groups. All households were given information about the health benefits of using the new cooking stove technology, while each treatment group received a different incentive to encourage adoption of the cleaner stoves.
A - Comparison: Stoves offered at full price (600 households).
B - 50% Subsidy: Stoves offered at half price (500 households).
C - Full Price + Opinion Leaders: Stoves offered at full price and households were informed about the adoption decisions of community “opinion leaders” (500 households).
D - 50% Subsidy + Opinion Leaders: Stoves offered at half price and households were informed about the adoption decisions of community “opinion leaders” (500 households).
E - Men Free: Husbands given choice of a free portable or chimney stove (200 households).
F - Women Free: Wives given choice of a free portable or chimney stove (200 households).
G - Men 85%: Husbands given choice of 50Tk (US$0.70) portable stove or 250 Tk (US$3.50) chimney stove (200 households).
H - Women 85%: Wives given choice of 50Tk portable stove or 250 Tk chimney stove (200 households).
Households were given the option to purchase, but did not have to pay ahead of time. Some who said they would purchase did not actually do so when it was time for delivery.
Price played an important role in the adoption decision. Offering stoves at the 50% subsidy increased adoption by over 200%. For those who initially declined the offer, the most common reason given was "too expensive." Adoption of the new stoves was far from universal even when they were free, which suggests that there are also important non-price factors affecting households’ decisions to adopt a new technology.
Opinion leaders' influence was stronger for initial statements of adoption than actual adoption. Hearing that opinion leaders had chosen NOT to adopt had a stronger impact than hearing that they had chosen to adopt a new stove.
Women are more likely to accept an improved stove, and the health-saving chimney stove in particular compared to men, but women drop out at higher rates than men once any positive price is charged. Women thus exhibit a stronger preference for the health-saving stove, but find it difficult to act on those preferences under the more stringent liquidity constraints they face.
1 WHO, “What happens when children live in unhealthy environments?” Available from https://www.who.int/mediacentre/factsheets/fs272/en/.
2 Mark M. Pitt, Mark R. Rosenzweig, Md. Nazmul Hassan, 2006. “Sharing the Burden of Disease: Gender, the Household Division of Labor and the Health Effects of Indoor Air Pollution in Bangladesh and India,” CID Working Paper No. 119.
3 WHO (2008), “Bangladesh: Health Profile.” Available from https://www.who.int/gho/countries/bgd.pdf
Miller, Grant, and A. Mushfiq Mobarak. "Learning About New Technologies Through Social Networks: Experimental Evidence on Non-Traditional Stoves in Bangladesh." Working Paper, September 2013.
Mobarak, Ahmed Mushfiz, Puneet Dwivedi, Robert Bailis, Lynn Hildemann, and Grant Miller. "Low Demand for Nontraditional Cookstove Technologies." Proceedings of the National Academy of Sciences (PNAS) 109(27): 10815-20.
Miller, Grant, and A. Mushifq Mobarak. "Gender Differences in Preferences, Intra-Household Externalities, and the Low Demand for Improved Cookstoves." Working Paper, Stanford University, January 2013.
Arif, Tamid, Anik Ashraf, Grant Miller, Ahmed Mushfiqu Mobarak, Nasima Akter, ARM Mehrab Ali, MA Quaiyum Sarkar, Lynn Hildemann, Nepal C Dey, Mizanur Rahman, Puneet Dwivedi, and Paul Wise. "Promotion of Improved Cookstove in Rural Bangladesh." Working Paper No. 22, BRAC, May 2011.