One of the core policies of most developing countries has been to improve the educational achievement of children. Traditionally, increasing school enrollment rates through supply-side interventions (e.g., in providing infrastructure, teaching support, and learning materials) has attracted widespread attention, and consequently most countries are on track to achieve universal access to primary education (Millennium Development Goal 2) (Pritchett and Banerji, 2013). As celebrated in United Nations (2015), indeed, the primary school net enrollment rate in the developing world has reached 91% in 2015. The number of children not attending primary school has also halved between 2000 and 2015. This praiseworthy accomplishment of school enrollment, however, has not necessarily resulted in improved learning outcomes, which has made the overall effectiveness of formal education questionable and caused many to rethink alternative educational interventions (Hanushek and Woessmann, 2011). Recent rigorous studies involving randomized control trials (RCTs) have provided valuable evidence regarding the effectiveness of various interventions on the quality of education and student learning, such as teachers’ incentives (Duflo et al., 2012; Glewwe et al., 2010), remedial tutors (Banerjee et al., 2007), class size (Duflo et al., 2015), and computer-assisted learning (Beuermann et al., 2015; Mo et al., 2013); however, these studies still center around school inputs.

An important – but apparently neglected – aspect of previous studies is that students’ learning depends on the after-school home-study environment, which is based on learning support (such as parental engagement or private tutoring for homework support) and learning-conducive inputs (such as adequate nighttime lighting for study). It is generally believed that after-school home-study enhances students’ understanding of what they are taught at school (Copper et al., 2006; Dang, 2007; Dufur et al., 2013; Stinebrickner and Stinebrickner, 2008). As many students in developing countries are expected to work during the day to help their families, it seems critical that they should use the nighttime effectively for study.

Despite the importance of nighttime study, universal access to electricity has been inadequate and challenging for many low-income countries. As of 2013, the number of people in developing countries who live without access to electricity numbered 1.3 billion, of whom the majority resided in rural areas (IEA, 2013). Over 80% of these “energy poor” households, which lack access to reliable energy for lighting, generally depend on biomass- or fuel-based traditional lighting sources, including kerosene lamps, which are incapable of producing sufficient illumination. It is possible that students with insufficient nighttime lighting could systematically under-perform, as studying under unreliable and dim lighting conditions could make their learning less productive (Alstone et al., 2010). It could also be the case that these students have access to irregular and limited opportunities for nighttime study, as biomass fuels and kerosene are expensive, often comprising approximately 10% of the total household expenditure of the poor (see Bacon et al., 2010 and Maliti and Mnenwa, 2011). Furthermore, students who study under biomass lighting report poor visual performance, fatigue, and eye strain (Mills, 2014).

2