Marketing Cook-Stoves to Address Indoor Air Pollution

Project Summary

Our research addresses the low uptake of improved cookstoves in developing countries.  Improved stoves have positive health and environmental impacts by reducing indoor air pollution (IAP).  Biomass combustion using traditional cookstoves is thought to be the main contributor to IAP, a principal culprit of acute respiratory infections in children worldwide.  Black carbon emission from traditional cook-stoves is an important contributor to climate change as well.  Despite these hazards, half of the world’s population continues to rely on traditional biomass-burning stoves for cooking.

Although simple technologies to reduce IAP exist, efforts to promote the adoption of these “improved cook-stoves” have proven ineffective.  Governments and international organizations have begun to take notice of the issue – in 2010, the Global Alliance for Clean Cookstoves was formed, with the goal of 100 million households adopting improved cookstoves by 2020. With over $250 million in projected funding, it is important to be able to effectively allocate spending to target potential consumers.

We conducted a randomized controlled study of 3000 households in 60 villages in two rural districts in Bangladesh to analyze improved cookstove adoption under eight conditions.  The study design allows us to estimate the effectiveness of different interventions to promote cookstove adoption through subsidies, information about health benefits, marketing campaigns aimed at women and men, and using social networks to overcome aversions to changes in traditional behavior.

Our results suggest that global health practitioners need to recognize that developing country consumers are utility (rather than health) maximizers, and are already largely aware of the hazards of indoor air pollution caused by traditional cookstoves. Therefore, marketing which focuses on highlighting these effects is likely to miss the mark. Instead, marketing should be tailored to address the specific demand-side aversions present in the target market.

Women have a stronger preference for improved cookstoves than men (and prefer healthy stoves in particular); however, they appear to lack the decision-making power to purchase the cookstoves.  Women are more likely to take and use stoves that are offered for free, but have much greater refusal rates when even small prices are charged.  The twin problems suggest that one cannot market only to women in Bangladesh (they do not have the authority to purchase stoves), or only to men (they have a lower preference for improved stoves).  The marketing must address both the men’s and women’s preferences and constraints, and thus bundling the product with a characteristic men value (e.g. a cleaner stove that also generates electricity to charge cell phones), may be a promising strategy.

Research Partners:

  • Grant Miller (Stanford Medical School), Research and Evaluation Division (BRAC), Lynn Hildemann (Stanford Civil Engineering), Paul Wise (Stanford Medical School)

Research Papers

  • A.M. Mobarak et al. (2012).  “Low Demand for Nontraditional Cookstove Technologies.”  Proceedings of the National Academy of Sciences 109(27): 10815-10820.
    Abstract: Biomass combustion with traditional cookstoves causes substantial environmental and health harm. Nontraditional cookstove technologies can be efficacious in reducing this adverse impact, but they are adopted and used at puzzlingly low rates. This study analyzes the determinants of low demand for nontraditional cookstoves in rural Bangladesh by using both stated preference (from a nationally representative survey of rural women) and revealed preference (assessed by conducting a cluster-randomized trial of cookstove prices) approaches. We find consistent evidence across both analyses suggesting that the women in rural Bangladesh do not perceive indoor air pollution as a significant health hazard, prioritize other basic developmental needs over nontraditional cookstoves, and overwhelmingly rely on a free traditional cookstove technology and are therefore not willing to pay much for a new nontraditional cookstove. Efforts to improve health and abate environmental harm by promoting nontraditional cookstoves may be more successful by designing and disseminating nontraditional cookstoves with features valued more highly by users, such as reduction of operating costs, even when those features are not directly related to the cookstoves’ health and environmental impacts.
  • G. Miller & A.M. Mobarak (2011).  “Gender Differences in Preferences, Intra-Household Externalities and the Low Demand for Improved Cookstoves.” Revise and Resubmit: The Economic Journal

    Abstract: This paper examines whether an intra-household externality prevents adoption of a technology with substantial implications for population health and the environment: improved cookstoves. Motivated by a model of intra-household decision-making, the experiment markets stoves to husbands or wives in turn at randomly varying prices. We find that women – who bear disproportionate cooking costs – have stronger preference for healthier stoves, but lack the authority to make purchases. Our findings suggest that if women cannot make independent choices about household resource use, public policy may not be able to exploit gender differences in preferences to promote technology adoption absent broader social change.

Policy Briefs

Press & Blog Coverage

Follow-up (Second Round) Social Network Surveys Funded by the International Growth Center and the Yale Climate and Energy Initiative 

The follow-up builds on a randomized intervention study that identifies the relative quantitative importance of a variety of socio-economic factors (price, lack of information, intra-household gender-specific preferences) that inhibit widespread cook-stove adoption in Bangladesh. We re-visit the same set of villages and strategically market to the friends, relatives and neighbors of our first round study participants in order to understand how best to use social networks to disseminate the new technology.

Taking advantage of different types of social network relationships (e.g. extended family members living within the same compound as our first-round households versus friends living further away in the village, or the relatives of the woman who cooks versus her husband’s relatives), we can learn about underlying mechanisms through which networks influence adoption decisions.  Our experimental design will vary the identity of network households to whom different types of information pass (e.g. friends living farther away only get to taste the food cooked with the new stove while extended family members living in close proximity also observe smoke emissions and have opportunities to try cooking with the new stove).  We will also collect detailed survey data on the nature of the interactions between all network members to pinpoint underlying mechanisms, such as a second round household’s propensity to adopt as a function of tasting food cooked with the stove versus their direct experience cooking with the stove, or directly observing smoke emissions.

Description of Social Network Follow-up (Download)

With a grant from Yale Climate and Energy Institute, further follow-up research and collaboration aims to engineer a clean, efficient, and context-appropriate cook-stove in rural Bangladesh.  This cook-stove solution will require novel engineering combined with socio-economic analyses of the constraints to new technology adoption, and environmental science consideration of resource constraints and consequences of use.  Supplementary experiments in our pre-existing field experiment locations in rural Bangladesh will also allow us to investigate the role of non-traditional factors in deterring adoption, which will help inform the design of the new Yale Stove for Bangladesh.  Our empirical strategy will leverage the fact that we already have randomized variation in adoption of new improved stoves among stoves among Bangladeshi households from previous experiments.  The engineering component of our team will then obtain very detailed information about the attributes of new stoves that matter most in determining adoption rates, and this will ultimately lead to a better and more appropriately designed stove.

Research Partners: Rob Bailis (Yale School of Forestry and Environmental Studies), Alessandro Gomez (Yale Mechanical Engineering)