Mobile-based digital initiatives have emerged as a popular tool for governments, NGOs, and the private sector to influence individual behaviour. With thousands of initiatives spanning sectors including education, agriculture, finance, health, and governance (GSMA 2020), these programmes take advantage of the widespread adoption of mobile phones to deliver messages at scale and at a low cost. In many low-income countries (LICs), where basic phones are still more common than smartphones (Pew Research 2019), text message-based programmes are a particularly practical and inexpensive option. However, their limitations – such as character constraints and reliance on top-down communication – raise questions about the effectiveness of these programmes. As a result, there is significant interest in evaluating their cost-effectiveness and exploring whether specific design and implementation choices could strengthen their impact.
In agriculture, mobile-based extension programmes hold significant promise for disseminating information about modern inputs and management practices to millions of smallholder farmers who would otherwise be difficult to reach through in-person visits. While we are still learning about the impacts of various of these digital initiatives, existing summaries of these evaluations have characterised the results as mixed (Aker et al. 2016, Deichmann et al. 2016). Some studies report positive and significant changes in farmer behaviour, while others find statistically insignificant effects. However, these mixed results and null effects could stem from measurement issues or small sample sizes that lack sufficient power to detect impacts. Low statistical power is particularly concerning when evaluating low-cost programmes such as those relying on text messages because even small impacts might be sufficient for these programmes to be considered cost-effective.
Six digital programmes that aimed to encourage farmers to experiment with agricultural inputs
In a forthcoming paper with Matthew Lowes, Robert On, and Giulia Zane (Fabregas et al. forthcoming), we evaluate six different text message-based agricultural extension programmes that collectively reached over 128,000 farmers in Kenya and Rwanda. These programmes were implemented by three organisations: a public entity (the Kenya Agriculture and Livestock Research Organization, KALRO), a partnership between non-profits (Innovations for Poverty Action and Precision Development, IPA/PxD), and a social enterprise (One Acre Fund, 1AF). All programmes targeted smallholder maize farmers, sending text messages with information about recommended inputs, focusing particularly on agricultural lime (a soil additive used to reduce soil acidity that was relatively unknown in these areas).
While the programmes shared a common objective – to encourage farmers to experiment with locally appropriate inputs – their implementation differed based on the specific constraints and opportunities faced by each organisation. These variations included farmer recruitment strategies, the design and framing of messages, the range of recommended inputs and practices, the emphasis on tailoring information to local soil conditions, the use of behavioural nudges, the frequency of messages, and the availability of supplementary support such as phone calls.
We partnered with these organisations to conduct experimental evaluations of each programme. To increase statistical power and formally test for impact heterogeneity across evaluations, we also conducted a meta-analysis. A key strength of our approach is the use of large sample sizes, which allow us to detect small effect sizes. Additionally, for each project we can use objective measures of farmer behaviour, such as administrative data on input purchases, to reduce concerns that observed impacts are simply driven by experimenter demand effects. For some projects, this administrative data is complemented by self-reported survey data.
Figure 1 Effects on recommended inputs and practices
