Fuel transition and time-saving: evidence from longitudinal survey and multivalued treatment effects

We study how transitions from biomass to liquefied petroleum gas (LPG) affect household time use and cooking experience in rural India. Using a two-period household panel from six states (2015–2018), we implement a multivalued difference-in-differences design that balances baseline covariates while differencing out time-invariant unobservables. We examine both complete (biomass→LPG) and incomplete (biomass→mixed) transitions and use downward moves away from LPG as a falsification check. A complete transition reduces daily cooking time by about 10% (20 minutes on a 201-minute baseline) and time per cooking event by 12%. An incomplete transition yields smaller time savings (about 7%). Beyond meal preparation, a clean switch cuts daily fuel-procurement time by roughly 48% (18 minutes on a 36.8-minute baseline), whereas switching to mixed fuels produces only modest reductions (about 11%). Reverse transitions (LPG→mixed/solid) substantially increase time spent on both activities, strengthening a causal interpretation. Perceptions improve with a clean switch – households report less smoke, less difficulty, and less time consumption – though they are more likely to view LPG as expensive. Taken together, the results show that the largest time savings arise only with a complete transition, with meaningful gains on both cooking and fuel-procurement margins.