Stove use: Initial household take-up of the (almost free) new stoves was high, but over time households generally chose to let the stoves fall into disrepair and used them less frequently. In the first two years, households that received stoves in the first wave were 65 percent more likely to have a Gram Vikas improved stove than comparison houses. However, by year three, this number had fallen to 44 percent. Further, households that obtained new stoves continued to use the traditional one in addition. On average, households that received stoves cooked only about 3 more of their meals per week using improved stoves than the comparison group.
Smoke exposure: Households that were eligible for stoves showed little improvement in smoke exposure. Household members were tested for the levels of Carbon Monoxide (CO) in exhaled breath to measure for smoke inhalation. For the household’s primary cook, CO exposure fell by 7.5 percent during the first year but there was little change for other women or children. However, this effect for the primary cooks disappeared after the first year.
Health status: Given that there was little to no change in smoke exposure, any health effects are unlikely to be due to decreased smoke inhalation. Respiratory tests of lung functioning, as well as a battery of health measures, both observed and self-reported, such as blood pressure, cough, cold and infant health outcomes, confirms that being offered a stove had no impact on health outcomes.
Fuel Usage and Cost of stoves: The clean stoves were meant to decrease fuel usage, and therefore fuel costs, and decrease cooking time. They do not appear to have done either, although interestingly, households report that the new stoves performed well on both measures. The new stoves did require substantially more repair than traditional stoves.
Policy Lessons: In the context of a real, large-scale program, improved stoves were not used regularly, recipients did not make the necessary investments to maintain them properly, and proper use declined further over time. There were no observable effects on smoke inhalation, health, or fuel usage. More research needs to be done to identify stoves that people value enough to use regularly and are willing to devote the resources necessary to maintain them. And, it is vital that these technologies be rigorously tested in real-world conditions over long time horizons, since household behavior will determine their ultimate effectiveness.