In a previous post, I discussed the potential health
benefits for women and children associated with the use of biomass
cookstove. Today I would like to talk about another potential benefit for the
biomass cookstove users: financial savings. Specifically, I will talk about
the discrepancy between the theoretical impact of the improved cookstoves on
household expenditure and what actually happens in practice.
Let’s start with the theory of change that can
explain the financial benefit of the biomass cookstove. As I said before, many
families in rural Indonesia use three stone fire as their cooking method.
However, a lot of families are using kerosene cookstoves too (96% of the
families that we visited in Kupang, 54% in Soe and 52% in Kefa). Besides being
unhealthy, this cooking method is expensive. A liter of kerosene costs around
5,000 Indonesian rupiees (0.39 dollars) and the average kerosene consumption per
week is 5.61 L in Kupang, 2.91 L in Soe and 4.36 L in Kefa. Because biomass
cookstoves do not require kerosene and they only need firewood, which can be
collected for free, biomass cookstoves have the potential of significantly reducing household expenditure.
While in theory the biomass cookstove can
reduce household expenditure, in practice, financial benefits are less than
expected. In order to understand this difference between the theory and what
actually happens in the field, it is important to highlight one of the results of our research: most people use multiple cooking methods, not only one. Specifically,
55% of those we interviewed use two or more cooking methods. In the same way, biomass
cookstove users combined this cookstove with other methods. In this context,
where there is no full transition to biomass cookstove, it makes sense that the
benefits of the cookstove are less than expected.
So let’s discuss the actual financial savings experienced
by people who use the cookstove. When using the improved cookstove, users
reduce their kerosene consumption for cooking by 41%, from approximately 25,000
rupiees per week to 10,000[1].
This benefit is realized most by users who are able to collect firewood.
However, when users have to buy wood to use the cookstove, it seems that there
is no income saving.
What is
interesting is that a rigorous impact evaluation of improved cookstoves in
India by a HKS professor (Hanna, Duflo and Greenstone, 2012) found a similar
result: “treatment households that received the improved stoves still continued
to use their traditional stoves in conjunction with the new ones” and,
consequently, “the treatment did not affect fuel costs”.
These two pieces of evidence show that the impact
of technologies in the real-world can be really different from their effect
under laboratory conditions. It is clear that individuals’ behavior influences
social programs’ effectiveness and, consequently, this behavior should be taken
into account when designing public policies.
