How much are households willing to invest in hand hygiene enabling technologies? A randomised pricing experiment in Lusaka, Zambia

Access to a dedicated handwashing facility (HWF) increases handwashing with soap (HWWS), an effective behaviour for preventing respiratory and diarrheal disease. Achieving universal hand hygiene will require household investment of a HWF, yet the ability and willingness of end-users to meet these costs has received little attention in stated or revealed preference studies. This two-phase voucher-based randomised pricing experiment explored whether households in peri-urban Lusaka, Zambia were willing to invest in a HWF. In Phase 1, three HWFs were tested with 60 households using two of the three HWFs for two weeks (20 households per combination). There was strong preference for a locally manufactured bucket with a tap and metal stand (Kalingalinga bucket; 250 ZMW, ∼US$10), over high-cost (1000 ZMW, ∼US$38) and low-cost (100 ZMW, ∼US$4) pre-manufactured HWFs. In Phase 2, n=160 used the Kalingalinga bucket for two weeks. At the end of the trial period, participants received a 50 ZMW gift (∼US$2) and a randomly assigned discount voucher (20%, 40%, 60%, 80%; 40 households per group), before deciding whether to purchase the HWF. Ninety-eight percent (39/40) of households offered an 80% discount purchased the HWF (effective price: 0 ZMW), compared with 30% (12/40) offered a 20% discount (effective price: 150 ZMW). Predictive modelling estimated that 50% of households would purchase at an effective price of 103 ZMW (∼40% of the retail price). Despite declining the purchase offer, all non-purchasing households reported positive stated willingness-to-pay, suggesting latent demand. Findings highlight the need for financial interventions that make desirable HWFs affordable.