Deconstructing the (un)affordability of clean cooking fuels through a randomized trial in rural Tanzania

Low-income users struggle to save for clean cooking fuel costs. We test whether a lockbox intervention paired with micro-saving nudges could alleviate the unaffordability of clean fuels. In a year-long stepped-wedge randomized control trial in Tanzania (n = 511), we find that compared to savings nudges only, a lockbox and savings nudges increased annual refills of liquefied petroleum gas (LPG) by 1.4 (0.054 per 2 weeks ([95% confidence interval: 0.043, 0.066], P < 0.0001)) and minimally decreased firewood use but had no effect on lags between LPG refills or the frequency of LPG and charcoal use. We find that easing liquidity constraints is insufficient for exclusive LPG use when LPG is the financial responsibility of only women, who ration LPG purchases to meet other household needs and social expectations. The financial and gendered realities of low-income consumers demand clean energy policies beyond easing liquidity constraints or targeted subsidies.