Low-income solar adopters are more likely to refer others to a fully subsidized solar programme when referral rewards are combined with an appeal to reciprocity and a simplified referral process, leading to five times as many solar contracts as when referral rewards are used alone. The findings highlight behavioural science strategies that administrators of low-income energy assistance programmes can use to cost-effectively accelerate programme uptake.
Recommendations for policy: Relying on financial rewards alone to encourage referrals for a low-income solar programme leaves many peer referrals — and subsequently solar installations — unrealized.Complementing referral rewards with programme simplification and an appeal to reciprocity can increase the number of referrals and resulting solar contracts by several-fold, at less cost per contract.Combining referral rewards, reciprocity, and programme simplification is more effective at attracting first-time referrers than either rewards alone or rewards combined with reciprocity.Reciprocity and simplification have trade-offs in terms of the timing, quality, and relative cost of the referrals generated, giving administrators flexibility depending on their programme objectives.